Posts Tagged ‘information’

How to build Linux logging bash shell script write_log, logging with Named Pipe buffer, Simple Linux common log files logging with logger command

Monday, August 26th, 2019

how-to-build-bash-script-for-logging-buffer-named-pipes-basic-common-files-logging-with-logger-command

Logging into file in GNU / Linux and FreeBSD is as simple as simply redirecting the output, e.g.:
 

echo "$(date) Whatever" >> /home/hipo/log/output_file_log.txt


or with pyping to tee command

 

echo "$(date) Service has Crashed" | tee -a /home/hipo/log/output_file_log.txt


But what if you need to create a full featured logging bash robust shell script function that will run as a daemon continusly as a background process and will output
all content from itself to an external log file?
In below article, I've given example logging script in bash, as well as small example on how a specially crafted Named Pipe buffer can be used that will later store to a file of choice.
Finally I found it interesting to mention few words about logger command which can be used to log anything to many of the common / general Linux log files stored under /var/log/ – i.e. /var/log/syslog /var/log/user /var/log/daemon /var/log/mail etc.
 

1. Bash script function for logging write_log();


Perhaps the simplest method is just to use a small function routine in your shell script like this:
 

write_log()
LOG_FILE='/root/log.txt';
{
  while read text
  do
      LOGTIME=`date "+%Y-%m-%d %H:%M:%S"`
      # If log file is not defined, just echo the output
      if [ “$LOG_FILE” == “” ]; then
    echo $LOGTIME": $text";
      else
        LOG=$LOG_FILE.`date +%Y%m%d`
    touch $LOG
        if [ ! -f $LOG ]; then echo "ERROR!! Cannot create log file $LOG. Exiting."; exit 1; fi
    echo $LOGTIME": $text" | tee -a $LOG;
      fi
  done
}

 

  •  Using the script from within itself or from external to write out to defined log file

 

echo "Skipping to next copy" | write_log

 

2. Use Unix named pipes to pass data – Small intro on what is Unix Named Pipe.


Named Pipe –  a named pipe (also known as a FIFO (First In First Out) for its behavior) is an extension to the traditional pipe concept on Unix and Unix-like systems, and is one of the methods of inter-process communication (IPC). The concept is also found in OS/2 and Microsoft Windows, although the semantics differ substantially. A traditional pipe is "unnamed" and lasts only as long as the process. A named pipe, however, can last as long as the system is up, beyond the life of the process. It can be deleted if no longer used.
Usually a named pipe appears as a file, and generally processes attach to it for IPC.

 

Once named pipes were shortly explained for those who hear it for a first time, its time to say named pipe in unix / linux is created with mkfifo command, syntax is straight foward:
 

mkfifo /tmp/name-of-named-pipe


Some older Linux-es with older bash and older bash shell scripts were using mknod.
So idea behind logging script is to use a simple named pipe read input and use date command to log the exact time the command was executed, here is the script.

 

#!/bin/bash
named_pipe='/tmp/output-named-pipe';
output_named_log='
/tmp/output-named-log.txt ';

if [ -p $named_pipe ]; then
rm -f $named_pipe
fi
mkfifo $named_pipe

while true; do
read LINE <$named_pipe
echo $(date): "$LINE" >>/tmp/output-named-log.txt
done


To write out any other script output and get logged now, any of your output with a nice current date command generated output write out any output content to the loggin buffer like so:

 

echo 'Using Named pipes is so cool' > /tmp/output-named-pipe
echo 'Disk is full on a trigger' > /tmp/output-named-pipe

  • Getting the output with the date timestamp

# cat /tmp/output-named-log.txt
Mon Aug 26 15:21:29 EEST 2019: Using Named pipes is so cool
Mon Aug 26 15:21:54 EEST 2019: Disk is full on a trigger


If you wonder why it is better to use Named pipes for logging, they perform better (are generally quicker) than Unix sockets.

 

3. Logging files to system log files with logger

 

If you need to do a one time quick way to log any message of your choice with a standard Logging timestamp, take a look at logger (a part of bsdutils Linux package), and is a command which is used to enter messages into the system log, to use it simply invoke it with a message and it will log your specified output by default to /var/log/syslog common logfile

 

root@linux:/root# logger 'Here we go, logging'
root@linux:/root # tail -n 3 /var/log/syslog
Aug 26 15:41:01 localhost CRON[24490]: (root) CMD (chown qscand:qscand -R /var/run/clamav/ 2>&1 >/dev/null)
Aug 26 15:42:01 localhost CRON[24547]: (root) CMD (chown qscand:qscand -R /var/run/clamav/ 2>&1 >/dev/null)
Aug 26 15:42:20 localhost hipo: Here we go, logging

 

If you have took some time to read any of the init.d scripts on Debian / Fedora / RHEL / CentOS Linux etc. you will notice the logger logging facility is heavily used.

With logger you can print out message with different priorities (e.g. if you want to write an error message to mail.* logs), you can do so with:
 

 logger -i -p mail.err "Output of mail processing script"


To log a normal non-error (priority message) with logger to /var/log/mail.log system log.

 

 logger -i -p mail.notice "Output of mail processing script"


A whole list of supported facility named priority valid levels by logger (as taken of its current Linux manual) are as so:

 

FACILITIES AND LEVELS
       Valid facility names are:

              auth
              authpriv   for security information of a sensitive nature
              cron
              daemon
              ftp
              kern       cannot be generated from userspace process, automatically converted to user
              lpr
              mail
              news
              syslog
              user
              uucp
              local0
                to
              local7
              security   deprecated synonym for auth

       Valid level names are:

              emerg
              alert
              crit
              err
              warning
              notice
              info
              debug
              panic     deprecated synonym for emerg
              error     deprecated synonym for err
              warn      deprecated synonym for warning

       For the priority order and intended purposes of these facilities and levels, see syslog(3).

 


If you just want to log to Linux main log file (be it /var/log/syslog or /var/log/messages), depending on the Linux distribution, just type', even without any shell quoting:

 

logger 'The reason to reboot the server Currently was a System security Update

 

So what others is logger useful for?

 In addition to being a good diagnostic tool, you can use logger to test if all basic system logs with its respective priorities work as expected, this is especially
useful as I've seen on a Cloud Holsted OpenXEN based servers as a SAP consultant, that sometimes logging to basic log files stops to log for months or even years due to
syslog and syslog-ng problems hungs by other thirt party scripts and programs.
To test test all basic logging and priority on system logs as expected use the following logger-test-all-basic-log-logging-facilities.sh shell script.

 

#!/bin/bash
for i in {auth,auth-priv,cron,daemon,kern, \
lpr,mail,mark,news,syslog,user,uucp,local0 \
,local1,local2,local3,local4,local5,local6,local7}

do        
# (this is all one line!)

 

for k in {debug,info,notice,warning,err,crit,alert,emerg}
do

logger -p $i.$k "Test daemon message, facility $i priority $k"

done

done

Note that on different Linux distribution verions, the facility and priority names might differ so, if you get

logger: unknown facility name: {auth,auth-priv,cron,daemon,kern,lpr,mail,mark,news, \
syslog,user,uucp,local0,local1,local2,local3,local4, \
local5,local6,local7}

check and set the proper naming as described in logger man page.

 

4. Using a file descriptor that will output to a pre-set log file


Another way is to add the following code to the beginning of the script

#!/bin/bash
exec 3>&1 4>&2
trap 'exec 2>&4 1>&3' 0 1 2 3
exec 1>log.out 2>&1
# Everything below will go to the file 'log.out':

The code Explaned

  •     Saves file descriptors so they can be restored to whatever they were before redirection or used themselves to output to whatever they were before the following redirect.
    trap 'exec 2>&4 1>&3' 0 1 2 3
  •     Restore file descriptors for particular signals. Not generally necessary since they should be restored when the sub-shell exits.

          exec 1>log.out 2>&1

  •     Redirect stdout to file log.out then redirect stderr to stdout. Note that the order is important when you want them going to the same file. stdout must be redirected before stderr is redirected to stdout.

From then on, to see output on the console (maybe), you can simply redirect to &3. For example
,

echo "$(date) : Do print whatever you want logging to &3 file handler" >&3


I've initially found out about this very nice bash code from serverfault.com's post how can I fully log all bash script actions (but unfortunately on latest Debian 10 Buster Linux  that is prebundled with bash shell 5.0.3(1)-release the code doesn't behave exactly, well but still on older bash versions it works fine.

Sum it up


To shortlysummarize there is plenty of ways to do logging from a shell script logger command but using a function or a named pipe is the most classic. Sometimes if a script is supposed to write user or other script output to a a common file such as syslog, logger command can be used as it is present across most modern Linux distros.
If you have a better ways, please drop a common and I'll add it to this article.

 

What is inode and how to find out which directory is eating up all your filesystem inodes on Linux, Increase inode count on a ext3 ext4 and ufs filesystems

Tuesday, August 20th, 2019

what-is-inode-find-out-which-filesystem-or-directory-eating-up-all-your-system-inodes-linux_inode_diagram

If you're a system administrator of multiple Linux servers used for Web serving delivery / Mail server sysadmin, Database admin or any High amount of Drives Data Storage used for backup servers infra, Data Repository administrator such as Linux hosted Samba / CIFS shares, etc. or using some Linux Hosting Provider to host your website or any other UNIX like Infrastructure servers that demands a storage of high number of files under a Directory  you might end up with the common filesystem inode depletion issues ( Maximum Inode number for a filesystem is predefined, limited and depending on the filesystem configured size).

In case a directory stored files end up exceding the amount of possible addressable inodes could prevent any data to be further assiged and stored on the Filesystem.

When a device runs out of inodes, new files cannot be created on the device, even though there may be plenty free space available and the first time it happened to me very long time ago I was completely puzzled how this is possible as I was not aware of Inodes existence  …

Reaching maximum inodes number (e.g. inode depletion), often happens on Busy Mail servers (receivng tons of SPAM email messages) or Content Delivery Network (CDN – Website Image caching servers) which contain many small files on EXT3 or EXT4 Journalled filesystems. File systems (such as Btrfs, JFS or XFS) escape this limitation with extents or dynamic inode allocation, which can 'grow' the file system or increase the number of inodes.

 

Hence ending being out of inodes could cause various oddities on how stored data behaves or communicated to other connected microservices and could lead to random application disruptions and odd results costing you many hours of various debugging to find the root cause of inodes (index nodes) being out of order.

In below article, I will try to give an overall explanation on what is an I-Node on a filesystem, how inodes of FS unit could be seen, how to diagnose a possible inode poblem – e.g.  see the maximum amount of inodes available per filesystem and how to prepare (format) a new filesystem with incrsed set of maximum inodes.

 

What are filesystem i-nodes?

 

This is a data structure in a Unix-style file system that describes a file-system object such as a file or a directory.
The data structure described in the inodes might vary slightly depending on the filesystem but usually on EXT3 / EXT4 Linux filesystems each inode stores the index to block that contains attributes and disk block location(s) of the object's data.
– Yes for those who are not aware on how a filesystem is structured on *nix it does allocate all stored data in logical separeted structures called data blocks. Each file stored on a local filesystem has a file descriptor, there are virtual unit structures file tables and each of the inodes that are a reference number has a own data structure (inode table).

Inodes / "Index" are slightly unusual on file system structure that stored the access information of files as a flat array on the disk, with all the hierarchical directory information living aside from this as explained by Unix creator and pioneer- Dennis Ritchie (passed away few years ago).

what-is-inode-very-simplified-explanation-diagram-data

Simplified explanation on file descriptors, file table and inode, table on a common Linux filesystem

Here is another description on what is I-node, given by Ken Thompson (another Unix pioneer and father of Unix) and Denis Ritchie, described in their paper published in 1978:

"    As mentioned in Section 3.2 above, a directory entry contains only a name for the associated file and a pointer to the file itself. This pointer is an integer called the i-number (for index number) of the file. When the file is accessed, its i-number is used as an index into a system table (the i-list) stored in a known part of the device on which the directory resides. The entry found thereby (the file's i-node) contains the description of the file:…
    — The UNIX Time-Sharing System, The Bell System Technical Journal, 1978  "


 

What is typical content of inode and how I-nodes play with rest of Filesystem units?


The inode is just a reference index to a data block (unit) that contains File-system object attributes. It may include metadata information such as (times of last change, access, modification), as well as owner and permission data.

 

On a Linux / Unix filesystem, directories are lists of names assigned to inodes. A directory contains an entry for itself, its parent, and each of its children.

Structure-of-inode-table-on-Linux-Filesystem-diagram

 

Structure of inode table-on Linux Filesystem diagram (picture source GeeksForGeeks.org)

  • Information about files(data) are sometimes called metadata. So you can even say it in another way, "An inode is metadata of the data."
  •  Inode : Its a complex data-structure that contains all the necessary information to specify a file. It includes the memory layout of the file on disk, file permissions, access time, number of different links to the file etc.
  •  Global File table : It contains information that is global to the kernel e.g. the byte offset in the file where the user's next read/write will start and the access rights allowed to the opening process.
  • Process file descriptor table : maintained by the kernel, that in turn indexes into a system-wide table of files opened by all processes, called the file table .

The inode number indexes a table of inodes in a known location on the device. From the inode number, the kernel's file system driver can access the inode contents, including the location of the file – thus allowing access to the file.

  •     Inodes do not contain its hardlink names, only other file metadata.
  •     Unix directories are lists of association structures, each of which contains one filename and one inode number.
  •     The file system driver must search a directory looking for a particular filename and then convert the filename to the correct corresponding inode number.

The operating system kernel's in-memory representation of this data is called struct inode in Linux. Systems derived from BSD use the term vnode, with the v of vnode referring to the kernel's virtual file system layer.


But enough technical specifics, lets get into some practical experience on managing Filesystem inodes.
 

Listing inodes on a Fileystem


Lets say we wan to to list an inode number reference ID for the Linux kernel (files):

 

root@linux: # ls -i /boot/vmlinuz-*
 3055760 /boot/vmlinuz-3.2.0-4-amd64   26091901 /boot/vmlinuz-4.9.0-7-amd64
 3055719 /boot/vmlinuz-4.19.0-5-amd64  26095807 /boot/vmlinuz-4.9.0-8-amd64


To list an inode of all files in the kernel specific boot directory /boot:

 

root@linux: # ls -id /boot/
26091521 /boot/


Listing inodes for all files stored in a directory is also done by adding the -i ls command flag:

Note the the '-1' flag was added to to show files in 1 column without info for ownership permissions

 

root@linux:/# ls -1i /boot/
26091782 config-3.2.0-4-amd64
 3055716 config-4.19.0-5-amd64
26091900 config-4.9.0-7-amd64
26095806 config-4.9.0-8-amd64
26091525 grub/
 3055848 initrd.img-3.2.0-4-amd64
 3055644 initrd.img-4.19.0-5-amd64
26091902 initrd.img-4.9.0-7-amd64
 3055657 initrd.img-4.9.0-8-amd64
26091756 System.map-3.2.0-4-amd64
 3055703 System.map-4.19.0-5-amd64
26091899 System.map-4.9.0-7-amd64
26095805 System.map-4.9.0-8-amd64
 3055760 vmlinuz-3.2.0-4-amd64
 3055719 vmlinuz-4.19.0-5-amd64
26091901 vmlinuz-4.9.0-7-amd64
26095807 vmlinuz-4.9.0-8-amd64

 

To get more information about Linux directory, file, such as blocks used by file-unit, Last Access, Modify and Change times, current External Symbolic or Static links for filesystem object:
 

root@linux:/ # stat /etc/
  File: /etc/
  Size: 16384         Blocks: 32         IO Block: 4096   catalog
Device: 801h/2049d    Inode: 6365185     Links: 231
Access: (0755/drwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2019-08-20 06:29:39.946498435 +0300
Modify: 2019-08-14 13:53:51.382564330 +0300
Change: 2019-08-14 13:53:51.382564330 +0300
 Birth: –

 

Within a POSIX system (Linux-es) and *BSD are more or less such, a file has the following attributes[9] which may be retrieved by the stat system call:

   – Device ID (this identifies the device containing the file; that is, the scope of uniqueness of the serial number).
    File serial numbers.
    – The file mode which determines the file type and how the file's owner, its group, and others can access the file.
    – A link count telling how many hard links point to the inode.
    – The User ID of the file's owner.
    – The Group ID of the file.
    – The device ID of the file if it is a device file.
    – The size of the file in bytes.
    – Timestamps telling when the inode itself was last modified (ctime, inode change time), the file content last modified (mtime, modification time), and last accessed (atime, access time).
    – The preferred I/O block size.
    – The number of blocks allocated to this file.

 

Getting more extensive information on a mounted filesystem


Most Linuxes have the tune2fs installed by default (in debian Linux this is through e2fsprogs) package, with it one can get a very good indepth information on a mounted filesystem, lets say about the ( / ) root FS.
 

root@linux:~# tune2fs -l /dev/sda1
tune2fs 1.44.5 (15-Dec-2018)
Filesystem volume name:   <none>
Last mounted on:          /
Filesystem UUID:          abe6f5b9-42cb-48b6-ae0a-5dda350bc322
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery sparse_super large_file
Filesystem flags:         signed_directory_hash
Default mount options:    (none)
Filesystem state:         clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              30162944
Block count:              120648960
Reserved block count:     6032448
Free blocks:              13830683
Free inodes:              26575654
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      995
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         8192
Inode blocks per group:   512
Filesystem created:       Thu Sep  6 21:44:22 2012
Last mount time:          Sat Jul 20 11:33:38 2019
Last write time:          Sat Jul 20 11:33:28 2019
Mount count:              6
Maximum mount count:      22
Last checked:             Fri May 10 18:32:27 2019
Check interval:           15552000 (6 months)
Next check after:         Wed Nov  6 17:32:27 2019
Lifetime writes:          338 GB
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:              256
Required extra isize:     28
Desired extra isize:      28
Journal inode:            8
First orphan inode:       21554129
Default directory hash:   half_md4
Directory Hash Seed:      d54c5a90-bc2d-4e22-8889-568d3fd8d54f
Journal backup:           inode blocks


Important note to make here is file's inode number stays the same when it is moved to another directory on the same device, or when the disk is defragmented which may change its physical location. This also implies that completely conforming inode behavior is impossible to implement with many non-Unix file systems, such as FAT and its descendants, which don't have a way of storing this invariance when both a file's directory entry and its data are moved around. Also one inode could point to a file and a copy of the file or even a file and a symlink could point to the same inode, below is example:

$ ls -l -i /usr/bin/perl*
266327 -rwxr-xr-x 2 root root 10376 Mar 18  2013 /usr/bin/perl
266327 -rwxr-xr-x 2 root root 10376 Mar 18  2013 /usr/bin/perl5.14.2

A good to know is inodes are always unique values, so you can't have the same inode number duplicated. If a directory is damaged, only the names of the things are lost and the inodes become the so called “orphan”, e.g.  inodes without names but luckily this is recoverable. As the theory behind inodes is quite complicated and is complicated to explain here, I warmly recommend you read Ian Dallen's Unix / Linux / Filesystems – directories inodes hardlinks tutorial – which is among the best academic Tutorials explaining various specifics about inodes online.

 

How to Get inodes per mounted filesystem

 

root@linux:/home/hipo# df -i
Filesystem       Inodes  IUsed   IFree IUse% Mounted on

 

dev             2041439     481   2040958   1% /dev
tmpfs            2046359     976   2045383   1% /run
tmpfs            2046359       4   2046355   1% /dev/shm
tmpfs            2046359       6   2046353   1% /run/lock
tmpfs            2046359      17   2046342   1% /sys/fs/cgroup
/dev/sdb5        1221600    2562   1219038   1% /usr/var/lib/mysql
/dev/sdb6        6111232  747460   5363772  13% /var/www/htdocs
/dev/sdc1      122093568 3083005 119010563   3% /mnt/backups
tmpfs            2046359      13   2046346   1% /run/user/1000


As you see in above output Inodes reported for each of mounted filesystems has a specific number. In above output IFree on every mounted FS locally on Physical installed OS Linux is good.


Here is an example on how to recognize a depleted Inodes on a OpenXen Virtual Machine with attached Virtual Hard disks.

linux:~# df -i
Filesystem         Inodes     IUsed      IFree     IUse%   Mounted on
/dev/xvda         2080768    2080768     0      100%    /
tmpfs             92187      3          92184   1%     /lib/init/rw
varrun            92187      38          92149   1%    /var/run
varlock            92187      4          92183   1%    /var/lock
udev              92187     4404        87783   5%    /dev
tmpfs             92187       1         92186   1%    /dev/shm

 

Finding files with a certain inode


At some cases if you want to check all the copy files of a certain file that have the same i-node pointer it is useful to find them all by their shared inode this is possible with simple find (below example is for /usr/bin/perl binary sharing same inode as perl5.28.1:

 

ls -i /usr/bin/perl
23798851 /usr/bin/perl*

 

 find /usr/bin -inum 435308 -print
/usr/bin/perl5.28.1
/usr/bin/perl

 

Find directory that has a large number of files in it?

To get an overall number of inodes allocated by a certain directory, lets say /usr /var

 

root@linux:/var# du -s –inodes /usr /var
566931    /usr
56020    /var/

To get a list of directories use by inode for a directory with its main contained sub-directories sorted from 1 till highest number use:
 

du -s –inodes * 2>/dev/null |sort -g

 

Usually running out of inodes means there is a directory / fs mounts that has too many (small files) that are depleting the max count of possible inodes.

The most simple way to list directories and number of files in them on the server root directory is with a small bash shell loop like so:
 

for i in /*; do echo $i; find $i |wc -l; done


Another way to identify the exact directory that is most likely the bottleneck for the inode depletion in a sorted by file count, human readable form:
 

find / -xdev -printf '%h\n' | sort | uniq -c | sort -k 1 -n


This will dump a list of every directory on the root (/) filesystem prefixed with the number of files (and subdirectories) in that directory. Thus the directory with the largest number of files will be at the bottom.

 

The -xdev switch is used to instruct find to narrow it's search to only the device where you're initiating the search (any other sub-mounted NAS / NFS filesystems from a different device will be omited).

 

Print top 10 subdirectories with Highest Inode Usage

 

Once identifed the largest number of files directories that is perhaps the issue, to further get a list of Top subdirectories in it with highest amount of inodes used, use below cmd:

 

for i in `ls -1A`; do echo "`find $i | sort -u | wc -l` $i"; done | sort -rn | head -10

 

To list more than 10 of the top inodes used dirs change the head -10 to whatever num needed.

N.B. ! Be very cautious when running above 2 find commands on a very large filesystems as it will be I/O Excessive and in filesystems that has some failing blocks this could create further problems.

To omit putting a high I/O load on a production filesystem, it is possible to also use du + very complex regular expression:
 

cd /backup
du –inodes -S | sort -rh | sed -n         '1,50{/^.\{71\}/s/^\(.\{30\}\).*\(.\{37\}\)$/\1…\2/;p}'


Results returned are from top to bottom.

 

How to Increase the amount of Inodes count on a new created volume EXT4 filesystem

Some FS-es XFS, JFS do have an auto-increase inode feature in case if their is physical space, whether otheres such as reiserfs does not have inodes at all but still have a field reported when queried for errors. But the classical Linux ext3 / ext4 does not have a way to increase the inode number on a live filesystem. Instead the way to do it there is to prepare a brand new filesystem on a Disk / NAS / attached storage.

The number of inodes at format-time of the block storage can be as high as 4 billion inodes. Before you create the new FS, you have to partition the new the block storage as ext4 with lets say parted command (or nullify the content of an with dd to clean up any previous existing data on a volume if there was already existing data:
 

parted /dev/sda


dd if=/dev/zero of=/dev/path/to/volume


  then format it with this additional parameter:

 

mkfs.ext4 -N 3000000000 /dev/path/to/volume

 

Here in above example the newly created filesystem of EXT4 type will be created with 3 Billion inodes !, for setting a higher number on older ext3 filesystem max inode count mkfs.ext3 could be used instead.

Bear in mind that 3 Billion number is a too high number and if you plan to have some large number of files / directories / links structures just raise it up to your pre-planning requirements for FS. In most cases it will be rarely anyone that want to have this number higher than 1 or 2 billion of inodes.

On FreeBSD / NetBSD / OpenBSD setting inode maximum number for a UFS / UFS2 (which is current default FreeBSD FS), this could be done via newfs filesystem creation command after the disk has been labeled with disklabel:

 

freebsd# newfs -i 1024 /dev/ada0s1d

 

Increase the Max Count of Inodes for a /tmp filesystem

 

Sometimes on some machines it is necessery to have ability to store very high number of small files (e.g. have a very large number of inodes) on a temporary filesystem kept in memory. For example some web applications served by Web Server Apache + PHP, Nginx + Perl-FastCGI are written in a bad manner so they kept tons of temporary files in /tmp, leading to issues with exceeded amount of inodes.
If that's the case to temporary work around you can increase the count of Inodes for /tmp to a very high number like 2 billions using:

 

mount -o remount,nr_inodes=<bignum> /tmp

To make the change permanent on next boot if needed don't forget to put the nr_inodes=whatever_bignum as a mount option for the temporary fs to /etc/fstab

Eventually, if you face this issues it is best to immediately track which application produced the mess and ask the developer to fix his messed up programs architecture.

 

Conclusion

 

It was explained on the very common issue of having maximum amount of inodes on a filesystem depleted and the unpleasent consequences of inability to create new files on living FS.
Then a general overview was given on what is inode on a Linux / Unix filesystem, what is typical content of inode, how inode addressing is handled on a FS. Further was explained how to get basic information about available inodes on a filesystem, how to get a filename/s based on inode number (with find), the well known way to determine inode number of a directory or file (with ls) and get more extensive information on a FS on inodes with tune2fs.
Also was explained how to identify directories containing multitudes of files in order to determine a sub-directories that is consuming most of the inodes on a filesystem. Finally it was explained very raughly how to prepare an ext4 filesystem from scratch with predefined number to inodes to much higher than the usual defaults by mkfs.ext3 / mkfs.ext4 and *bsds newfs as well as how to raise the number of inodes of /tmp tmpfs temporary RAM filesystem.

Play Midis on Linux / Make Linux MIDI Ready for the Future – Enable embedded MIDI music to play in a Browser, Play MIDIs with VLC and howto enjoy Midis in Text Console

Wednesday, October 4th, 2017

how-to-play-midi-on-gnu-linux-in-graphic-environment-console-and-browser-midi-synthesizer-and-linux-tux-together

 

Play Midis on Linux or Make Linux MIDI Ready for the Future – Enable embedded MIDI music to play in a Browser, Play MIDIs with VLC and howto enjoy Midis in Text Console HOWTO

 

Playing MIDI has been quite a lot of fun historically,

if you grow up in the days when personal computers were still young and the Sound Blaster was a luxury, before the raise of Mp3 music format, you have certainly enjoyed the beeping of PC Speaker and later on during 386 and 486 / 586 computers the enjoyment of playing tracked music such as S3M and MOD,

in that good days playing MIDI music was the only alternative for PC maniacs who doesn't own a CD Drive (which itself) was another luxury and even thouse who had a CD ROM device, were mainly playing music in CD audio format (.CDA).
Anyhow MIDI was a cheap and a CPU unintensive way to listen to equivalent of favourite popular Audio Songs and for those who still remember many of the songs were recreated in MIDI format, just with a number of synthesized instruments without any voice (as MIDI is usually).

The same was true also for the good old days of raise of Mobile Phones, when polyphonic was a standard as CPU power was low MIDI was a perfect substitute for the CPU heavy Encoded MP3s / OGG and other formats that required a modern for that time Intel CPU running in 50+ Mhz usually 100 / 166Mhz was perfect for the days to play Mp3 but still even on that PCs we listened to Midi songs.

Therefore if you're one of those people like me who still enjoy to play some Midi Music in the year 2017 and feel a bit like Back into the Future movie and a Free Software fan and user, especially if you're a novice GNU  / Linux Free Software user, you will be unpleasently surprised that most today's default Linux distributions doesn't have an easy way to play Midi music format out of the box right after install.

Hence below article aims to give you an understanding on

How you can play Midi Music on GNU / Linux Operating System

First, lets Prepare to load necessery Linux kernel modules to make sure MIDI can be played by soundcard:

In /etc/modules make sure you have the following list of modules loaded:
 

linux-desktop:~# cat /etc/modules
3c59x
snd-emu10k1
snd-pcm-oss
snd-mixer-oss
snd-seq-oss

!Note the modules are working as of time of writting and in time can change to some other modules, depending on how the development of ALSA (Advanced Linux Sound Architecture) goes, and if the developers decide to rename the upmentioned modules

If you just have added the modules to /etc/modules with vim / nano to reload modules into the Linux kernel run:

 

linux-desktop:~# modprobe -a


Secondly, Installing a whole bunch of MIDI music related program tools can be achieved in Debian by installing the multimedia-midi package, e.g.:

 

linux-desktop:~# apt-get install –yes multimedia-midi

 

1. Playing Midi in Graphical environment with a double click using VLC


How to make MIDI easy listanable in Linux graphical environment like GNOME / KDE / XFCE desktop ?

 

If you want to make Midi music execution sa easy as  just clicking on the .MIDI file format on Linux you can do that with a midi extension available for VLC (Video Lan Client) Universal Multi Platform Media Player player

To install it on Debian Ubuntu GNU / Linux
 

# apt-get install –yes vlc-plugin-fluidsynth

 

Необходимо е да се изтеглят 6754 B архиви.
След тази операция ще бъде използвано 35,8 kB допълнително дисково пространство.
Изт:1 http://deb.debian.org/debian stretch/main amd64 vlc-plugin-fluidsynth amd64 2.2.6-1~deb9u1 [6754 B]
Изтеглени 6754 B за 0с (33,6 kB/сек)           
Selecting previously unselected package vlc-plugin-fluidsynth:amd64.
(Reading database … 382976 files and directories currently installed.)
Preparing to unpack …/vlc-plugin-fluidsynth_2.2.6-1~deb9u1_amd64.deb …
Unpacking vlc-plugin-fluidsynth:amd64 (2.2.6-1~deb9u1) …
Setting up vlc-plugin-fluidsynth:amd64 (2.2.6-1~deb9u1) …
Processing triggers for libvlc-bin:amd64 (2.2.6-1~deb9u1) …


Besides making your MIDI play on the GUI environment easy as a a point and click VLC will also be able to play MIDIs on GNU / Linux from your favourite browser (nomatter Firefox / Chrome or Opera), even though the player would play in a new PopUP Window it is easy to select once MIDI file from a random website for example – here is a directory listing of Webserver with Doom II Soundtrack in MIDI format , click over any file from list and Choose option for VLC to always remember that MIDI files has to be opened with VLC player.
 


2. Enable Firefox / IceWeasel browser to Support Website embedded MIDI files

 

 

So VLC could make you listen the downloadable MIDIs from Web pages but,
 

What if you have stumbled on an old website which was configured with very OLD HTML Code to play some nice music (or even different MIDI songs) for each part of the website (for each webpage) and you want to have the Websites created with embedded MIDIs to automatically play on Linux oncce you visit the site?


Sadly default support in Browser for MIDI across all GNU / Linux, I've used so far never worked out of the box, not that still anyone is developing modern websites with MIDIs, but still for the sake of backward compitability and for sake of interactivity it is worthy to enable embedded MIDI support in Linux

But with a couple of tunings as usual GNU / Linux can do almost everything, so here is how to enable embedded browser support for Midi on Linux (That should work with minor modifications not only on Debian / Ubuntu / ArchLinux but also on Fedoras, CentOS etc.
If you try it on any of this distributions, please drop a short comment and tell me in few lines how you made embedded midi worked on that distros.

 

apt-get install –yes timidity mozplugger

Next do restart firefox

Sometimes in order to work you might need to delete /home/[YOUR_USERNAME]/.mozilla/pluginreg.dat and restart firefox again, e.g. make a backup and give it a try:

 

cp -rpf /home/hipo/.mozilla/pluginreg.dat /home/hipo/.mozilla/pluginreg.dat.bak
rm -f /home/hipo/.mozilla/pluginreg.dat

 

Another good tip as talking for embedding MIDI support is to embed XPDF to render PDF pages inside the Browser, by default this is done by GNOME's Evince PDF reader but as it is sometimes buggy and might crash it is generally a good idea to switch to xpdf instead, if for some reason PDF is not directly displaying in browser or suddenly stopped working after some distro uipgrade, you might want to do below as well:
 

apt-get install xpdf

vim /etc/mozpluggerrc

Fin d and Comment out the line starting with:

It should look like this afterwards:

 Repeat Swallow ….
 

text/x-pdf: pdf: PDF file
#      repeat swallow(documentShell) fill: acroread -geometry +9000+9000 +useFrontEndProgram "$file"
        repeat noisy swallow(Xpdf) fill: xpdf -g +9000+9000 "$file"
        repeat noisy swallow(gv) fill: gv –safer –quiet –antialias -geometry +9000+9000 "$file"


 

3. Play Midi music in Linux text console / terminal


There is a console tool that historically has been like the Linux standard for playing midis over the years as I remember, its called timidity

 


To install timidity on .Deb based Linux:
 

linux-desktop:~$ su root
Password:
linux-desktop:~# apt-get install –yes timidity

Необходимо е да се изтеглят 0 B/580 kB архиви.
След тази операция ще бъде използвано 0 B допълнително дисково пространство.
(Reading database … 382981 files and directories currently installed.)
Preparing to unpack …/timidity_2.13.2-40.5_amd64.deb …
Unpacking timidity (2.13.2-40.5) over (2.13.2-40.5) …
Processing triggers for menu (2.1.47+b1) …
Processing triggers for man-db (2.7.6.1-2) …
Setting up timidity (2.13.2-40.5) …
Processing triggers for menu (2.1.47+b1) …

 

To test your new MIDI Synthesizer tool and make the enjoyment full you can download Doom 2 extracted MIDI Soundtrack from here
 

Once you have downloaded above Metal MIDI DOOM old school arcade soundtrack and untarred it into your home directory be it ~/doom-midis

A remark to make here is timidity is quite CPU intensive, but on modern Dual and Quad-Core PC Notebooks, the CPU load is not of a big concern.

To test and play with timidity:
 

linux-desktop~$ timidity ~/mp3/midis/*


timidity-playing-doom-midi-bunny-song-on-debian-stretch-gnome-terminal-screenshot
 

hipo@jericho:~/mp3/midis$ aplaymidi -l
 Port    Client name                      Port name
 14:0    Midi Through                     Midi Through Port-0
128:0    TiMidity                         TiMidity port 0
128:1    TiMidity                         TiMidity port 1
128:2    TiMidity                         TiMidity port 2
128:3    TiMidity                         TiMidity port 3

 


We have also the playmidi  (simple midi text console terminal player), which historically was working quite decent and I use it to in the past on my RedHat 6.0 and RedHat 7.0 to listen to my .MID format files but unfortunately as of time of writting something is wrong with it, so when I try to play MIDIs with it instead of timidity I get this erro:

 

$ playmidi *.mid
Playmidi 2.4 Copyright (C) 1994-1997 Nathan I. Laredo, AWE32 by Takashi Iwai
This is free software with ABSOLUTELY NO WARRANTY.
For details please see the file COPYING.
open /dev/sequencer: No such file or directory

Even though I tried hard to resolve that error by loading various midi related MIDI modules and following a lot of the suggestions online on how to  make /dev/sequencer work again it was all no luck.
 

Some people back in the distant year 2005, reported the problem was solved by simply loading snd-seq

But as of time of writting:

 

# modprobe snd-seq

 

Some people said in archlinux's Forum

/dev/sequencer sequencer: No such file or directory

 

is solved by loading snd-seq-oss kernel module, but on my Debian Linux 9.1 Stretch, this ain't work as well :

 

root@jericho:/home/hipo/mp3/midis# modprobe snd-seq-oss
modprobe: FATAL: Module snd-seq-oss not found in directory /lib/modules/4.9.0-3-amd64
root@jericho:/home/hipo/mp3/midis# uname -a;
Linux jericho 4.9.0-3-amd64 #1 SMP Debian 4.9.30-2+deb9u5 (2017-09-19) x86_64 GNU/Linux


Another invention of mine was to try to also link /dev/snd/seq to /dev/sequencer but this produced no positive result either:

 

# ln -sf /dev/snd/seq /dev/sequencer
# ls -al /dev/sequencer
lrwxrwxrwx 1 root root 12 окт  4 16:48 /dev/sequencer -> /dev/snd/seq


Note that after lining in that way I got following error with my attempt to play MIDIs with playmidi

# playmidi *.mid
Playmidi 2.4 Copyright (C) 1994-1997 Nathan I. Laredo, AWE32 by Takashi Iwai
This is free software with ABSOLUTELY NO WARRANTY.
For details please see the file COPYING.
there is no soundcard


Anyhow on some other Linux distributions (especially with Older Kernel versions), some of the above 3 suggested Fix might work perfectly fine so if you have some time give it a try please and drop me  a comment on how it went, you will help the GNU / Linux community out there that way.

Well never mind the bollocks, so

Now back to where I started timidity even though it will play fine it will not give any indication on the lenght of the midi song (precious information such as how much time is left until the end is over).

Hence if you prefer a player that gives you an indicator on how much is left towards the end length of each of the played MIDI file you can give a try to wildmidi:

 

linux-desktop:~$ apt-cache show wildmidi|grep -i description -A 2

Description-en: software MIDI player
 Minimal MIDI player implementation based on the wildmidi library that
 can either dump to WAV or playback over ALSA. It is intended to

Description-md5: b4b34070ae88e73e3289b751230cfc89
Homepage: http://www.mindwerks.net/projects/wildmidi/
Tag: implemented-in::c, role::program, sound::midi, sound::player,

Description: software MIDI player
Description-md5: 4673a7051f104675c73eb344bb045607
Homepage: http://wildmidi.sourceforge.net/
Bugs: https://bugs.launchpad.net/ubuntu/+filebug


If yet not installed install it after becoming admin user:

 

linux-desktop:~$ su root
Password:

linux-desktop:~# apt-get install –yes wildmidi


wildmidi is much less CPU intensive (it uses gstreamer to play (Gstreamer – open source multimedia framework)

And next give it a try by running:

 

linux-desktop:~$ wildmidi ~/mp3/midis/*

 

wildmidi-midi-lenght-status-text-console-player-for-linux-ubuntu-debian-fedora-suse

 

 

4. Editting MIDI files with Free Software and Proprietary MIDI Editor Programs

 


If you want a professional software that can play Midi in a fuzzy interactive GUI way and have some extra possibilities to edit MIDIs and other format give a try to Muse Sequencer:
 

 

linux-desktop:~$ sudo apt-get install –yes muse

The following NEW packages will be installed:
  muse
0 upgraded, 1 newly installed, 0 to remove and 38 not upgraded.
Need to get 5814 kB of archives.
After this operation, 21.0 MB of additional disk space will be used.
Get:1 http://deb.debian.org/debian stretch/main amd64 muse amd64 2.1.2-3+b1 [5814 kB]
Fetched 5814 kB in 2s (2205 kB/s)                             
    are supported and installed on your system.
Preconfiguring packages …
Selecting previously unselected package muse.
(Reading database … 382981 files and directories currently installed.)
Preparing to unpack …/muse_2.1.2-3+b1_amd64.deb …
Unpacking muse (2.1.2-3+b1) …
Processing triggers for mime-support (3.60) …
Processing triggers for desktop-file-utils (0.23-1) …
Processing triggers for doc-base (0.10.7) …
Processing 1 added doc-base file…
Registering documents with scrollkeeper…
Processing triggers for man-db (2.7.6.1-2) …
Processing triggers for shared-mime-info (1.8-1) …
Unknown media type in type 'all/all'
Unknown media type in type 'all/allfiles'
Processing triggers for gnome-menus (3.13.3-9) …
Setting up muse (2.1.2-3+b1) …
Processing triggers for hicolor-icon-theme (0.15-1) …


 

Below is short description what Muse can do for you:

 

MusE is a MIDI/audio sequencer with recording and editing capabilities.
 Some Highlights:
 

  * Standard midifile (smf) import-/export.
  * Organizes songs in tracks and parts which you can arrange with
    the part editor.
  * MIDI editors: pianoroll, drum, list, controller.
  * Score editor with high quality postscript printer output.
  * Realtime: editing while playing.
  * Unlimited number of open editors.
  * Unlimited undo/redo.
  * Realtime and step-recording.
  * Multiple MIDI devices.
  * Unlimited number of tracks.
  * Sync to external devices: MTC/MMC, Midi Clock, Master/Slave.
  * Audio tracks, LADSPA host for master effects.
  * Multithreaded.
  * Uses raw MIDI devices.
  * XML project file.
  * Project file contains complete app state (session data).
  * Application spanning Cut/Paste Drag/Drop.

 

linux-desktop~:$ muse

muse-advanced-midi-editor-free-software-for-linux

 

Below is another non-free program that you might, try if MusE doesn't fit your needs (is not rich enough for editting capabilities is bitwig (though I don't recommend since it is not free software)

bitwig – Bitwig Studio is a multi-platform music-creation system for production, performance and DJing, with a focus on flexible editing tools and a super-fast workflow.
 


bitwig-midi-and-audio-non-free-software-advanced-useful-sound-editor-for-linx


 

5. Some examples for Text editing and MIDI Conversion to CSV and ABC file formats There is pretty much more

For the MIDI Extremists who or people that create MIDIs and want to learn how a MIDI is made (the content of it etc.), I suggest you take a look at these 3 command line MIDI editing / conversion tools
 

  • midi2abc – A little tool to create MIDI formats to ABC format
  • midi2csv – Conver tour Favourite MIDI files to CSV for educational purposes so see what Channels, Tracks and Time Intervals is a MIDI song mad
  • midicopy – Copy selected, track, channel, time interval of MIDI file to another MIDI file3

 

Well, that's all folks now enjoy your MIDIs and don't forget to donate, as I'm jobless at the moment and the only profit I make is just a few bucks out of advertisement on this blog.
 

Flight from Sofia Minsk via Moscow Sheremetevo airport a few impressions from Russia and Belarus

Sunday, April 17th, 2016

Sofia-Sheremetevo-Minsk-my-impressions-on-Russian-and-Belarusian-airport-what-it-is-like-in-Eurasian-Union

Thanks God, today we had a safe flight  for one more time with my wife Svetlana from Sofia  airport Vrazhdebna ( Terminal 2 )  to Minsk Belarus National Airport.
We travel 2 times to Belarus from Bulgaria (European Union) and though in Summer time tickets are more cheap and more regular and more convenient direct flights are available from Bulgaria to Minsk (Varna -> Minsk and Burgas -> Minsk) because of tourism the only way to travel quickly by plane to Minsk from Bulgaria is either via Moscow or via Istanbul as in the late days the political situation in Turkey is so ignited and the problem with these refugees and crazy bomb hihhadists is escalating we decided to not fly through Istanbul Ataturk airport even though the bit lower ticket prices.

The trip started from Sofia airport, there we had to go through the regular Metal Detector scan and removal of all metal things and going through the scan "gateway" doors. It seems after the last terrorist acts in Brussels Belgium and the risk for many other Islamic ones the security in airports was raised even further.

The distrust to the regular flight traveller like me has reached a crazy levels, these times besies the regular Metal detector, we were asked to give our hands and with a small device called "Trivka", were checked whether our skin has recently been exposed to explosive materials and stuff like this …

For both flights Sofia -> Moscow Sheremetevo and Sheremevo -> Minsk we flied with Aeroflot. This is not the first time we fly with Aeroflot and I think it will definitely not to be the last time. The airplanes we flight with were a new airplanes (SU) Sukhoi airplane and I enjoyed the flight.

My impression was the Russian pilots are "driving" / flying the plane very much like they drive an ordinary military airplane and that's quite fun as the airplane lift off and landing is done very rapidly exactly like being done with a military aircraft. Of course that could be my own gut feeling but it feels that way just to compare the aviators of other Westerner airplanes such as Boeng 737 / 777 does speed up before lift off much more easily so the flight out doesn't boost up so much adrenaline 🙂

The food in Sofia -> Moscow plane was quite decent too we were served the so common and valued in Russia, Belarus and Eurasian Union (EAC) juice called RICH before the meail toghether with some option for a beef meal or a chicken meal. The meal itself was worm and served in a board inside holding 2 cardboard boxes one containing the beef together with some spaghetti with steamed vegetables and the other one containing a tiny soared corny with a few pieces of beef (or pork) meet with two pieces of some healthy "black" rye bread pieces one of which was with some healthy sesame seeds accompanied by a small package of butter and some other souce. For a dessert  a delicious waffle like made of drought mashed fruits.

To be honest my first impression seeing that strange meal combination was not very positive, not to say that I honestly wanted to puke but after tasting it I would say I really liked it. Aeroflot offers also a vegetarianian menu but this has to be pre-ordered in advance and as I didn't ordered it earlier but for next time if it is a fasting period before Easter or Christmas I would definitely pre-order a vegeraranian meal.

What I truly liked about Aeroflot's Sukhoi SuperJet 100-95 with which we flight is the the simplistic design, no extras inside the plane no annoying monitors that show you all the time the altitude and reporting over which country you're flying and generally no useless and often unwanted information.
However we were reported by the pilot a couple of times some information such as that we're flying over Brest and Minsk, but of course the English of the pilot was hard to understand. Well the radio from the pilot on the airplane is definitely something that didn't impressed me as in any other western airplane the radio connection from pilot is much more clearly heard but I guess this can be solved quickly.
The toilets in the airplane was also normal ones as in any other Western built Boeng, here is time to say it was always intesting for me the wiping of the toilet once the wipe off button is pressed a small hole is opened letting some air directly from outside to pull off what is inside the toilet and that quickly cleans it up 🙂

Entering the airplane was done through an attachable cordon (air tunnel) and not like with my earlier flights in which we were driven to the airplane by an ordinary bus.  

moscow-sheremetevo-terminal-2

Sheremetevo is really huge airport and what impressed me is the fact Sheremetevo's airport letters were written in pure cyrillic, something surely unique to see for any person coming from the west.

First impression from Moscow Sheremetevo if compared to Shiphol airport in Holland or Heatrow port in London is Sheremetevo is much more calm and quiet, the airport looks feels relaxing and cozy even though its outlook is a bit old fashioned. The marketing and advertisement ads all around the place and complexity of Sheremetevo is much less if compared to any other huge International airport and some things are made in a typical Russian manner, even the number of products being sold in the airport are much less than in any western airport, though there is plenty of caffeterias and restaurants to have lunch / dinner.

Moscow-Shermeetevo-free-duty-shops-and-terminal-D-red-cooridor-signatures

The simplicity on Sheremetevo airport is really a great thing as even the monitors showing up information for the flights are displaying the information in a very understanable and simply way even though possessing generally an old fashioned DOS like outlook if compared to the modern European Union / United States airports.
While waiting on Terminal D for the onboarding to flight Moscow -> Minsk, I had an amazing view of the airports airplanes, moving all around.
This is the first time I saw so many airplanes gathered on one place even though I've flight via Sheremetevo previous times this is the first time I'm starting to understand how big is really Sheremetevo.

One unfortunate fact about the flught was that our luggage was not transferred directly to Minsk Belarus but sent from Sofia to Sheremetevo and then we had to wait for some time to pick it up right after we've been checked by the border control kiosk.
There by the border police Russian lady I had to answer her few questions and she filled me a small list called "Migration card" blank for the Transfer visa.
Oh yes, I almost forgot in order to fly through Russian to another country inside the Eurasian Union such as Belarus, you need to have a Russian Transfer Visa which is being applied for from Russian embassy in Bulgaria.
The Russian Transit flight  VISA costs 60 EUR (if it is to be made from 4 to 10 days) and for a 3 days creation of VISA it costs 95 EURO.

Sheremetevo_airport_Saint_Nicolas_Eastern_Orthodox-Chapel

One very great thing about Sheremetevo which I liked so much as I'm an Eastern Orthodox Christian is the existence of the Eastern Orthodox Chapel in honour of Saint Nicolas the Myrh-Bearer who is in our Christian faith considered to be a protector of all travelers. Thus if like me you happen to be a Christian and you're flying via Moscow it is very nice to drop by for a few minutes in St. Nicolas chapel to light up a candle and pray to the saint with a beseach for a safe flight.

 

Sheremetevo-airport-Saint_Nicolas_Chapel-iconostas-icons-of-the-Savior-Jesus-Christ-and-Virgin_Mary
Here in Minsk the airport is also very cozy and warm (especially the old terminal), so one have a relaxing feeling once in Minsk.
Minsk airport is also very well organized and well maintained so to be honest it looks to me personally more beautiful than Sheremetevo.

Minsk-National-airport-logo

To transfer to the 2nd airplane that flight from Moscow Sheremetevo to Minsk we needed to make transfer from Terminal F (where we arrived) to Terminal D which is the terminal that runs the local Eurasian Union flights from Russia to Belarus (note that Russian, Belarus doesn't have a flight border so anyone flying from Russia to Belarus could fly freely and once you reach Belarus, you're not being checked at all from any border control and that's pretty cozy because we didn't have to be checked for a second time once we reached Minsk.

minsk-inside-airport-shops-and-infrastructure

My impression from Minsk National airport is that it is a nice mixture of communistic remains architecture and modern architecture.
There are plenty of private  busses (marshrutki) that goes every 15 minutes from Minsk airport which is 43 km from city center as well as an ordinary state bus that gues to the train station and city center.
The train station in Minsk is also on a very much Western level and for some things it is even better as it has a cheap shop, where you can buy food at same prices as in any other supermarket chain in Belarus. 
We travelled to train station and there what striked me is the touch screen interface allowing you to see various info about Minsk infrastructure the trains timing and even there was a video call to Train Station Staff to find out more about anything you can't find out yourself.

 

Check Windows Operating System install date, Full list of installed and uninstalled programs from command line / Check how old is your Windows installation?

Tuesday, March 29th, 2016

when-was-windows-installed-check-howto-from-command-line
Sometimes when you have some inherited Windows / Linux OS servers or Desktops, it is useful to be aware what is the Operating System install date. Usually the install date of the OS is closely to the date of purchase of the system this is especially true for Windows but not necessery true for Liunx based installs.

Knowing the install date is useful especially if you're not sure how outdated is a certain operating system. Knowing how long ago a current installation was performed could give you some hints on whether to create a re-install plans in order to keep system security up2date and could give you an idea whether the system is prone to some common errors of the time of installation or security flaws.

 

1. Check out how old is Windows install?

Finding out the age of WIndows installation can be performed across almost all NT 4.0 based Windowses and onwards, getting Winblows install date is obtained same way on both Windows XP / Vista/  7  and 8.

Besides many useful things such as detailed information about the configuration of your PC / notebook systeminfo could also provide you with install date, to do so just run from command line (cmd.exe).
 

C:\Users\hipo> systeminfo | find /i "install date"
Original Install Date:     09/18/13, 15:23:18 PM


check-windows-os-install-date-from-command-line-howto-screenshot

If you need to get the initial Windows system install date however it might be much better to use WMIC command to get the info:

 

 

C:\Users\hipo>WMIC OS GET installdate
InstallDate
20130918152318.000000+180


The only downside of using WMIC as you can see is it provides the Windows OS install date in a raw unparsed format, but for scripters that's great.

2. Check WIndows Installed and Uinstalled software and uptime from command line

One common other thing next to Windows install date is what is the Windows uptime, the easiest way to get that is to run Task Manager in command line run taskmgr

windows-task-manager-how-to-check-windows-operating-system-uptime-easily

For those who want to get the uptime from windows command line for scripting purposes, this can be done again with systeminfo cmd, i.e.:

 

C:\> systeminfo | find "System Boot Time:"
System Boot Time:          03/29/16, 08:48:59 AM


windows-os-command-to-get-system-uptime-screenshot

Other helpful Windows command liners you might want to find out about is getting all the Uninstalled and Installed programs from command line this again is done with WMIC

 

C:\> wmic /OUTPUT:my_software.txt product get name

 


get-a-full-list-of-installed-software-programs-on-windows-xp-vista-7-8-command-howto-screenshot

Alternative way to get a full list of installed software on Windows OS is to use Microsoft/SysInternals psinfo command:

 

C:\> psinfo -s > software.txt
C:\> psinfo -s -c > software.csv


If you need to get a complete list of Uinstalled Software using command line (e.g. for batch scripting) purposes, you can query that from Windows registry, like so:

 

C:\>reg query HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall


Command Output will be something like on below shot:

windows-OS-show-get-full-list-of-uninstalled-programs-using-a-command-line-screenshot

Well that's all folks 🙂

 

Windows: command to show CPU info, PC Motherboard serial number and BIOS details

Wednesday, March 2nd, 2016

windows-command-to-show-motherboard-bios-and-cpu-serials-and-specific-info-with-wmic

Getting CPU information, RAM info and other various hardware specifics on Windows from the GUI interface is pretty trivial from Computer -> Properties
even more specifics could be obtained using third party Windows software such as CPU-Z

Perhaps there are plenty of many other ones to get and log info about hardware on PC or notebook system, but for Windwos sysadmins especially ones who are too much in love with command prompt way of behaving and ones who needs to automatizate server deployment processes with BATCH (.BAT)  scripts getting quickly info about hardware on freshly installed remote host Win server with no any additional hardware info tools, you'll be happy to know there are command line tools you can use to get extra hardware information on Windows PC / server:

The most popular tool available to present you with some basic hardware info is of course systeminfo

 

C:\> systeminfo

Host Name:                 REMHOST
OS Name:                   Microsoft Windows Server 2012 R2 Standard
OS Version:                6.3.9600 N/A Build 9600
OS Manufacturer:           Microsoft Corporation
OS Configuration:          Member Server
OS Build Type:             Multiprocessor Free
Registered Owner:          Registrar
Registered Organization:   Registrar
Product ID:                00XXX-X0000-00000-XX235
Original Install Date:     17/02/2016, 11:38:39
System Boot Time:          18/02/2016, 14:16:48
System Manufacturer:       VMware, Inc.
System Model:              VMware Virtual Platform
System Type:               x64-based PC
Processor(s):              1 Processor(s) Installed.
                           [01]: Intel64 Family 6 Model 45 Stepping 7 GenuineInt
el ~2600 Mhz
BIOS Version:              Phoenix Technologies LTD 6.00, 11/06/2014
Windows Directory:         C:\Windows
System Directory:          C:\Windows\system32
Boot Device:               \Device\HarddiskVolume1
System Locale:             de;German (Germany)
Input Locale:              de;German (Germany)
Time Zone:                 (UTC+01:00) Amsterdam, Berlin, Bern, Rome, Stockholm,
 Vienna
Total Physical Memory:     4,095 MB
Available Physical Memory: 2,395 MB
Virtual Memory: Max Size:  10,239 MB
Virtual Memory: Available: 8,681 MB
Virtual Memory: In Use:    1,558 MB
Page File Location(s):     C:\pagefile.sys
Domain:                    dom1.domain.com
Logon Server:              \\DOM
Hotfix(s):                 148 Hotfix(s) Installed.
                           [01]: KB2894852
                           [02]: KB2894856
                           [03]: KB2918614
                           [04]: KB2919355
…..


Now though systeminfo's hardware details and installed Windows KBXXXXX OS Hotfix patches are getting lists the command does not provide you with info about  system’s BIOS, thus to get this info you'll have to use also wmic (Windows Management Instrumentation Command).
 

 

So What Is WMIC?

WMIC extends WMI for operation from several command-line interfaces and through batch scripts. Before WMIC, you used WMI-based applications (such as SMS), the WMI Scripting API, or tools such as CIM Studio to manage WMI-enabled computers. Without a firm grasp on a programming language such as C++ or a scripting language such as VBScript and a basic understanding of the WMI namespace, do-it-yourself systems management with WMI was difficult. WMIC changes this situation by giving you a powerful, user-friendly interface to the WMI namespace.

WMIC is more intuitive than WMI, in large part because of aliases. Aliases take simple commands that you enter at the command line, then act upon the WMI namespace in a predefined way, such as constructing a complex WMI Query Language (WQL) command from a simple WMIC alias Get command. Thus, aliases act as friendly syntax intermediaries between you and the namespace. For example, when you run a simple WMIC command such as

Here is how to wmic to get PC Motherboard serial numbers, CPU and BIOS details:

 

C:\> wmic bios get name,serialnumber,version

 

Above will print  name if your BIOS, current version and it’s serial number if there is any.

If you need to get more info about the specific Motherboard installed on host:

 

C:\> wmic csproduct get name,identifyingnumber,uuid

 

This command will show motherboard modification and it’s UUID

If you want to quickly get what is Windows running hardware CPU clock speed
 

C:\> wmic cpu get name,CurrentClockSpeed,MaxClockSpeed

 

Also if you have turbo boost CPUs above command will help you find what’s the Max Clock Speed your system is capable of for the current hardware configuration.

If you do have dynamic clock speed running, then add this line, will refresh and monitor the Clock speed every 1 second.
 

C:\> wmic cpu get name,CurrentClockSpeed,MaxClockSpeed /every:1

Actually wmic is a great tool

Howto Fix “sysstat Cannot open /var/log/sysstat/sa no such file or directory” on Debian / Ubuntu Linux

Monday, February 15th, 2016

sysstast-no-such-file-or-directory-fix-Debian-Ubuntu-Linux-howto
I really love sysstat and as a console maniac I tend to install it on every server however by default there is some <b>sysstat</b> tuning once installed to make it work, for those unfamiliar with <i>sysstat</i> I warmly recommend to check, it here is in short the package description:<br /><br />
 

server:~# apt-cache show sysstat|grep -i desc -A 15
Description: system performance tools for Linux
 The sysstat package contains the following system performance tools:
  – sar: collects and reports system activity information;
  – iostat: reports CPU utilization and disk I/O statistics;
  – mpstat: reports global and per-processor statistics;
  – pidstat: reports statistics for Linux tasks (processes);
  – sadf: displays data collected by sar in various formats;
  – nfsiostat: reports I/O statistics for network filesystems;
  – cifsiostat: reports I/O statistics for CIFS filesystems.
 .
 The statistics reported by sar deal with I/O transfer rates,
 paging activity, process-related activities, interrupts,
 network activity, memory and swap space utilization, CPU
 utilization, kernel activities and TTY statistics, among
 others. Both UP and SMP machines are fully supported.
Homepage: http://pagesperso-orange.fr/sebastien.godard/

 

If you happen to install sysstat on a Debian / Ubuntu server with:

server:~# apt-get install –yes sysstat


, and you try to get some statistics with sar command but you get some ugly error output from:

 

server:~# sar Cannot open /var/log/sysstat/sa20: No such file or directory


And you wonder how to resolve it and to be able to have the server log in text databases periodically the nice sar stats load avarages – %idle, %iowait, %system, %nice, %user, then to FIX that Cannot open /var/log/sysstat/sa20: No such file or directory

You need to:

server:~# vim /etc/default/sysstat


By Default value you will find out sysstat stats it is disabled, e.g.:

ENABLED="false"

Switch the value to "true"

ENABLED="true"


Then restart sysstat init script with:

server:~# /etc/init.d/sysstat restart

However for those who prefer to do things from menu Ncurses interfaces and are not familiar with Vi Improved, the easiest way is to run dpkg reconfigure of the sysstat:

server:~# dpkg –reconfigure


sysstat-reconfigure-on-gnu-linux

 

root@server:/# sar
Linux 2.6.32-5-amd64 (pcfreak) 15.02.2016 _x86_64_ (2 CPU)

0,00,01 CPU %user %nice %system %iowait %steal %idle
0,15,01 all 24,32 0,54 3,10 0,62 0,00 71,42
1,15,01 all 18,69 0,53 2,10 0,48 0,00 78,20
10,05,01 all 22,13 0,54 2,81 0,51 0,00 74,01
10,15,01 all 17,14 0,53 2,44 0,40 0,00 79,49
10,25,01 all 24,03 0,63 2,93 0,45 0,00 71,97
10,35,01 all 18,88 0,54 2,44 1,08 0,00 77,07
10,45,01 all 25,60 0,54 3,33 0,74 0,00 69,79
10,55,01 all 36,78 0,78 4,44 0,89 0,00 57,10
16,05,01 all 27,10 0,54 3,43 1,14 0,00 67,79


Well that's it now sysstat error resolved, text reporting stats data works again, Hooray! 🙂

Start Event Viewer from Command Line (Prompt) – eventvwr.msc to Debug Windows server issues

Friday, November 6th, 2015

eventvwrmsc-event-viewer-windows-7-screenshot-view-windows-log-and-dianose-errors

If you’re a sysadmin which needs to deal with Microsoft Windows servers locally or remotely via Remote Desktop RDP client (MSTSC.EXE) or inside a Windows Domain Controller, you will have to frequently debug Windows isseus or Application caused errors by reviewing debug information stored in Event Logs.

Event Viewer is a precious tool to debug often errors with missing libraries or failing programs on Windows boot and thus on M$ Windows it is the Swiss Army knife of sysadmin.
However as staring Event Viewer using the GUI menus, takes a lot of step and looses you time, e.g., you have to navigate to menus:

1. Start button Picture of the Start button
2. clicking Control Panel
3. clicking System and Security
4. clicking Administrative Tools
5.then double-clicking Event Viewer.‌
6. Granting Administrator permission required If you’re prompted for an administrator password or confirmation

It is much handier to just start it with a shortcut:

Press Windows (Button) + R
– To invoke run prompt

and type:

eventvwr.msc

In case if you’re running eventvwr.msc to connect to remote Windows Server run from command prompt (cmd.exe):

eventvwr-run-from-command-prompt-with-a-smart-shortcut-to-save-time-when-administrating-windows-servers

eventvwr.msc /computer=OTHER_Computer_Name

event-viewer-log-reader-and-debug-tool-for-windows-PC-and-windows-servers-adminsitration

How to query LDAP (Windows Domain Controller) directory entries from Linux – ldapsearch common searche examples

Tuesday, November 18th, 2014

active-directory-logo
If you have a hybrid network of Windows servers and computers in Active Directory (AD) Domain Names and Linux hosts hosting various Java / PHP / Python applications like many of the middle and big companies (organization) have, sooner or later you will have to deploy an application which uses some some user authentication from the Linux host to Windows Domain Controller, you will end up in need to be able to query the AD, which is using LDAP (Lightweight Directory Access Protocol) to store the AD user credentials and tons of other information important for proper Active Directory operations.

LDAP is a key industry standard for storing and accessing distributed directory information services over Internet Protocol (IP). LDAP is great for sharing of information about users, systems, networks, services, and applications throughout the network. The corporate world nowadays would have been impossible without LDAP.
As of time of writting latest RFC  (Resource for Comment) 4511 document describes industrial specification of LDAP version 3.0 and therefore this is the most often used and implemented version.

LDAP protocol supports generally following operations:

Adding, Delete, Bind (Authenticate to LDAP server), Delete Search and Compare, Modify and Modify DN (Distringuished Name)
Deleting recordsh

On Linux to retrieve / locate AD entries, there is ldapsearch  command which opens connection to LDAP host server port, with set username and password. ldapsearch tool makes its search based on a filter.

To have make and modify queries in LDAP from GNU / Linux you will have to have installed ldap-utils on Debian, i.e.:

apt-get –yes install ldap-utils


to have ldapseach, ldapmodify, ldapsearch ldappasswd on CentOS / Redhat Linux, you need openldap-clients.x86_64

yum -y install openldap-clients.x86_64

Returned result from ldapsearch clients will be returned in LDIF format (LDAP Data Interchange format).

ldapsearch basic format is like thsi:

ldapsearch [optional_options] [optional_search_filter] [optional_list_of_attributes]

ldapsearch could query (LDAP – ADs) in unencrypted form simple LDAP, encrypted form with SSL certificate (LDAPs) or through LDAP with STARTTLS.
Logically most organizations nowadays are using LDAPs, as it offers the highest level of security. Unencrypted LDAP servers listen usually on
port 389, LDAPs communicates on port 636 once an SSL handshake is made between client and server and LDAP with STARTTLS communicates on standard port 389.

Here is 3 examples of common  ldapsearch queries

1. Return all entries in LDAP server
 

ldapsearch -D "cn=directory manager" -w secret -p 389 -h ldap.your-organization.org -b "dc=your-organization,dc=com" -s sub "(objectclass=*)"


"objectclass=*" is a serch filter matching all entries in the directory (time and size limits on output limit set for the server will take affect)

2. Searching the Root DSE Entry

root DSE is special entry containing list of all suffixes supported by local Directory Server. Getting root DSE is done with  base of "", a search scope of base, and a filter of "objectclass=*"

ldapsearch -D "cn=directory manager" -w secret_pass -p 389 -h ldaps.your-organization.org  -b "dc=your-organization,dc=com" -s sub "cn=babs jensen"

 

3. Searching Directory Server Schema Entry

LDAP server stores all directory server schema in special entry cn=schema.
schema entry contains information on every object class and attribute defined for the Directory Server. Command to searches  contents of the cn=schema entry is:
 

ldapsearch -D "cn=directory manager" -w secret_pass -p 389 -h ldaps.your-organization.org -b "cn=schema" -s base "objectclass=*"


4. Check whether cn=My-Account1 account is working and enabled

ldapsearch -H ldaps://ldaps.your-organization.org -b o=my-org,c=bg -s sub -D cn=My-Account1,ou=users,ou=ABC,o=my-org,c=ABC -W '(&(cn=My-Acount1)(objectclass=my-org-Account))'


5. check all members of cn=MY_ADMINISTRATION

 

ldapsearch -H ldaps://ldaps.your-organization.org -b o=my-org,c=bg -s sub -D cn=My-Account1,ou=users,ou=ABC,o=my-org,c=ABC -W '(&(cn=MY_ADMINISTRATION)(member=*))'

 

6. check all members of all groups belonging to user
 

ldapsearch -H ldaps://ldaps.your-organization.org -b ou=ABC,ou=ABC1,ou=ABC2,ou=groups,ou=ABC,o=my-org,c=ABC -s sub -D cn=My-Account1,ou=users,ou=ABC,o=my-org,c=ABC -W '(cn=*)'
 

Whether ldapsearch queries are to be common and scripted or just for simplification of readability of query to LDAP it is useful to use LDAP_BASEDN – a query search base. By setting search base you can further omit in query -b

export LDAP_BASEDN="dc=your-organization,dc=com"
ldapsearch -D "cn=directory manager" -w secret_pass -p 389 -h ldap.your-organization.org "cn=labs jordan"

In Linux LDAP's open-source implementation is called OpenLDAP.
On Linux LDAP protocol can be easily integrated / used in combination with FTP servers (such as proftpd), DNS servers, Mail Servers (Courier), Samba servers, Radius (IP Telephony), sudo, as well as most programming languages such as PHP, Python etc.

Monitoring Disk use, CPU Load, Memory use and Network in one console ncurses interface – Glance

Thursday, August 14th, 2014

monitoring-disk-use-memory-cpu-load-and-network-in-one-common-interfaces-with-glances-Linux-BSD-UNIX
If you're Linux / UNIX / BSD system administrator you already have experience with basic admin's system monitoring:

  •     CPU load
  •     OS Name/Kernel version
  •     System load avarage and Uptime
  •     Disk and Network Input/Output I/O operations by interface
  •     Process statistics / Top loading processes etc.
  •     Memory / SWAP usage and free memory
  •     Mounted partitions


Such info is provided by command line tools such as:

top, df, free, sensors, ifconfig, iotop, hddtemp, mount, nfsstat, nfsiostat, dstat, uptime, nethogs iptraf

etc.

There are plenty of others advanced tools also Web based server monitoring visualization  tools, such as Monit, Icanga, PHPSysInfo, Cacti which provide you statistics on computer hardware and network utilization

So far so good, if you already are used to convenience of web *NIX based monitoring but you don't want to put load on the servers with such and you're lazy to write custom scripts that show most important monitoring information – necessery for daily system administration monitoring and prevention from downtimes and tracking bottlenecks you will be glad to hear about Glances
 

Glances is a free (LGPL) cross-platform curses-based monitoring tool which aims to present a maximum of information in a minimum of space, ideally to fit in a classical 80×24 terminal or higher to have additionnal information. Glances can adapt dynamically the displayed information depending on the terminal size. It can also work in a client/server mode for remote monitoring.


1. Installing Glances curses-based monitoring tool on Debian 7 / Ubuntu 13+ / Mint  Linux

We have to install python-pip (python package installer tool) to later install Glances

apt-get install –yes 'python-dev' 'python-jinja2' 'python-psutil'
                        'python-setuptools' 'hddtemp' 'python-pip' 'lm-sensors'


Before proceeding to install Glances to make Thermal sensors working (if supported by hardware) run:

 

 sensors-detect

Glances is written in Python and uses psutil library to obtain monitoring statistic values, thus it is necessery to install few more Python libraries:

pip install 'batinfo' 'pysensors'

If you're about to use pip – Python package installer tool, behind a proxy server use instead:
 

pip install –proxy=http://your-proxy-host.com:8080 'batinfo' 'pysensors'

Then install Glances script itself again using pip
 

pip install 'Glances'

Downloading/unpacking Glances
  Downloading Glances-2.0.1.tar.gz (3.3Mb): 3.3Mb downloaded
  Running setup.py egg_info for package Glances
    
Downloading/unpacking psutil>=2.0.0 (from Glances)
  Downloading psutil-2.1.1.tar.gz (216Kb): 216Kb downloaded
  Running setup.py egg_info for package psutil

Successfully installed Glances psutil

 

Then run glances from terminal
 

glances -t 3

-t 3 option tells glances to refresh collected statistics every 3 seconds

glances-console-monitoring-tool-every-systemad-ministrator-should-know-and-use-show-memory-disk-cpu-mount-point-statistics-in-common-shared-screen-linux-freebsd-unix

 

2. Installing Glances monitoring console tool on CentOS / RHEL / Fedora / Scientific Linux

Installing glances on CentOS 7 / Fedora and rest of RPM based distributions can be done by adding external RPM repositories, cause glances is not available in default yum repositories.

To enable Extra-packages repositories:
 

rpm -ivh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm


Then update yum to include new repository's packages into package list and install python-pip and python-devel rpms
 

yum update
yum install python-pip python-devel


Glances-console-server-stateScreenhot-on-CentOS-Linux-monitoring-in-ncurses-Linux-BSD

There is also FreeBSD port to install Glances on FreeBSD:
 

cd /usr/sysutils/py-glances
make install


Enjoy 🙂 !