Posts Tagged ‘Load’

Fix KDE Plasma fails to load: “All shell packages missing. This is an installation issue, please contact your distribution” in Kubuntu Linux

Friday, September 27th, 2019

Kubuntu_Linux-logo_and_wordmark-fix-plasma-graphical-environment

I've been called yesterday by a friend who has referred me to a friend of him Zvezdomir from Gabrovo who had installation of Kubuntu Desktop Linux by some other colleague but then suddenly the colleague decided to leave the country thus the Kubuntu become completely unmanaged.
In the spirit of Murphy's laws soon after it broke and as the HDD was filled with a lot of important pictures data I received the call with a beseech to help him fix his existing broken Kubuntu installation on the relatively old IBM thinkpad notebook. 
No problem,  I switched the role of a Linux Desktop user tech support  as it is part of daily job of every system admini to be on the hotline for computer medication and never say no to incoming requests 🙂

It seems the guy had messed up his Graphical Environment when as a Linux novice user decided to experiment with changing environments, he used to be using GNOME and then due to some issues with some of the Image Viewer eog – Eye of Gnome / Shotwell / Gpaint whose borders was not showing properly or something he decided to Switch to KDE Plasma. This was successful but as he continued to try out things on the Linux he broke it up badly so after the machine booted he was getting the error after boot of Xorg  Plasma was producing below error.

All-shell-packages-missing-This-is-an-installation-issue-please-contact-your-distribution

"All shell packages missing. This is an installation issue, please contact your distribution"

 


After spending about 30 minutes on the phone explaining him how to switch to Console as he had even no basic concepts about how to manage his Linux box, the problem was solved below are few steps taken to fix All shell packages missing issue

1. Press Ctrl + Alt + F2 Simultaneously

Usually historically switching to console on GNU / Linux was possible with CTRL + ALT + F1 but this was changed as often newer Linux distros do use TTY1 console to launch the X GUI environment.
Here we had some struggles to explain him where F1 as he thought he is supposed to press CTRL + ALT + S + 2 (perhaps misheard on the phone …) and was panicing how he is supposed to press 4 buttons simultaneously after a while it was cleared it is CTRL + ALT + F2 …
PS. In some of the other Ubuntus Lubuntu or older Ubuntus if CTRL + ALT + F2 doesn't work,

some of the other Virtual Text Consoles should be accessible with CTRL + ALT + F3CTRL + ALT + F4 etc.

2.  Login with your user login name

Once the login: field appears I had to explain him about 10 times how he should type his non-privileged user as it is always the case with computer novice. I had to stress here he should press Enter after the username / login is typed …

3. Become root (superuser) after standard login with:

 

sudo su

 

3. If the machine is not connected to internet (this might be the case if errors are produced on below 4. 5. steps)

Assuming you're already superuser (root) and you have no internet because the Network Manager is unable to connect due to failure of KDE Plasma to start, in order to connect to lets say already configured WI-Fi home wireless router,
restart networking with

 

service NetworkManager restart

 

Since internet connectivity will be required in order to be able to install the missing packages and update the package repositories, next test whether internet is reachable.

 

ping google.com
PING google.com (172.217.169.110) 56(84) bytes of data.
64 bytes from sof02s31-in-f14.1e100.net (172.217.169.110): icmp_seq=1 ttl=56 time=15.2 ms
64 bytes from sof02s31-in-f14.1e100.net (172.217.169.110): icmp_seq=2 ttl=56 time=11.5 ms
64 bytes from sof02s31-in-f14.1e100.net (172.217.169.110): icmp_seq=3 ttl=56 time=6.00 ms
^C
— google.com ping statistics —
3 packets transmitted, 3 received, 0% packet loss, time 5ms
rtt min/avg/max/mdev = 6.003/10.892/15.220/3.783 ms

N.B.! We had stumble blocks here too, as the Wi-Fi router seemed to be far away from the room where the PC was, after he moved to the other room where Signal was fine and re-issuing the service NetworkManager restart ping worked.

4. Next to get the latest list with available installable packages on the Ubuntu run the usual

 

apt-get update


5. Do install / reinstall kubuntu-desktop meta package

 

Finally to Fix the broken desktop GUI (that is not appearing instead of the Plasma login

 

apt-get install –yes kubuntu-desktop

 

Finally reboot the Laptop with reboot cmd:

reboot

On next boot Kubuntu's usual login screen should be as it used to be until you have broken your package system with tampering with the packages.

And Hooray ! It works again 🙂

By the way as I googled a bit to investigate futher, the problem seems to be common and the solution with a lot of fuzzling is given also pointed as an bug in Ubuntu's launchpad here

 

Monitor General Server / Desktop system health in console on Linux and FreeBSD

Tuesday, October 4th, 2011

slurm-output-monitoring-networking
saidar
is a text based ncurses program to display live statistics about general system health.

It displays in one refreshable screen (similar to top) statistics about server state of:
CPU, Load, Memory, Swap, Network, I/O disk operations
Besides that saidar supports a ncurses console colors, which makes it more funny to look at.
Saidar extracts the statistics for system state based on libgstrap cross platform statistics library about pc system health.

On Debian, Ubuntu, Fedora, CentOS Linuxes saider is available for install straight from distribution repositories.
On Debian and Ubuntu saidar is installed with cmd:

debian:~# apt-get install saidar
...

On CentOS and Fedora saidar is bundled as a part of statgrab-tools rpm package.
Installing it on 64 bit CentOS with yum is with command:

[root@centos ~]# yum install statgrab-tools.x86_64

Saidar is also available on FreeBSD as a part of the /usr/ports/devel/libgstrab, hence to use on my FreeBSD I had to install the libgstrab port:

freebsd# cd /usr/ports/devel/libstatgrab
freebsd# make install clean

Here is saidar running on my Desktop Debian on Thinkpad in color output:

debian:~# saidar -c

Saidar Linux General statistics Screenshot

I've seen many people, who use various shell scripts to output system monitoring information, this scripts however are often written to just run without efficiency in mind and they put some let's say 1% extra load on the system CPU. This is not the case with saidar which is written in C and hence the program is optimized well for what it does.

Update: Next to saidar I recommend you check out Slurm (Real Time Network Interface Monitor) it can visualizes network interface traffic using ascii graph such as on top of the article. On Debian and Ubuntu Slurm is available and easily installable via simple:
 

apt-get install –yes slurm

 

How to make GRE tunnel iptables port redirect on Linux

Saturday, August 20th, 2011

I’ve recently had to build a Linux server with some other servers behind the router with NAT.
One of the hosts behind the Linux router was running a Window GRE encrypted tunnel service. Which had to be accessed with the Internet ip address of the server.
In order < б>to make the GRE tunnel accessible, a bit more than just adding a normal POSTROUTING DNAT rule and iptables FORWARD is necessery.

As far as I’ve read online, there is quite of a confusion on the topic of how to properly configure the GRE tunnel accessibility on Linux , thus in this very quick tiny tutorial I’ll explain how I did it.

1. Load the ip_nat_pptp and ip_conntrack_pptp kernel module

linux-router:~# modprobe ip_nat_pptp
linux-router:~# modprobe ip_conntrack_pptp

These two modules are an absolutely necessery to be loaded before the remote GRE tunnel is able to be properly accessed, I’ve seen many people complaining online that they can’t make the GRE tunnel to work and I suppose in many of the cases the reason not to be succeed is omitting to load this two kernel modules.

2. Make the ip_nat_pptp and ip_nat_pptp modules to load on system boot time

linux-router:~# echo 'ip_nat_pptp' >> /etc/modules
linux-router:~# echo 'ip_conntrack_pptp' >> /etc/modules

3. Insert necessery iptables PREROUTING rules to make the GRE tunnel traffic flow

linux-router:~# /sbin/iptables -A PREROUTING -d 111.222.223.224/32 -p tcp -m tcp --dport 1723 -j DNAT --to-destination 192.168.1.3:1723
linux-router:~# /sbin/iptables -A PREROUTING -p gre -j DNAT --to-destination 192.168.1.3

In the above example rules its necessery to substitute the 111.222.223.224 ip address withe the external internet (real IP) address of the router.

Also the IP address of 192.168.1.3 is the internal IP address of the host where the GRE host tunnel is located.

Next it’s necessery to;

4. Add iptables rule to forward tcp/ip traffic to the GRE tunnel

linux-router:~# /sbin/iptables -A FORWARD -p gre -j ACCEPT

Finally it’s necessery to make the above iptable rules to be permanent by saving the current firewall with iptables-save or add them inside the script which loads the iptables firewall host rules.
Another possible way is to add them from /etc/rc.local , though this kind of way is not recommended as rules would add only after succesful bootup after all the rest of init scripts and stuff in /etc/rc.local is loaded without errors.

Afterwards access to the GRE tunnel to the local IP 192.168.1.3 using the port 1723 and host IP 111.222.223.224 is possible.
Hope this is helpful. Cheers 😉

Possible way to Improve wordpress performance with wp-config.php 4 config variables

Tuesday, March 6th, 2012

Wordpress improve performance wp-config.php logo chromium effect GIMP

Nowdays WordPress is ran by million of blogs and websites all around the net. I myself run wordpress for this blog in general wordpress behaves quite well in terms of performance. However as with time the visitors tend to increase, on frequently updated websites or blogs. As a consequence, the blog / website performance slowly starts to decrease as result of the MySQL server read / write operations creating I/O and CPU load overheads. Buying a new hardware and migrating the wordpress database is a possible solution, however for many small or middle size wordpress blogs en sites like mine this is not easy task. Getting a dedicated server or simply upgrading your home server hardware is expensive and time consuming process… In my efforts to maximize my hardware utilization and increase my blog decaying performance I've stumbled on the article Optimize WordPress performance with wp-config.php

According to the article there are 4 simple wp-config.php config directvies useful in decreasing a lot of queries to the MySQL server issued with each blog visitor.

define('WP_HOME','http://www.yourblog-or-siteurl.com');
define('WP_SITEURL','http://www.yourblog-or-siteurl.com');
define('TEMPLATEPATH', '/var/www/blog/wp-content/themes/default');
define('STYLESHEETPATH', '/var/www/blog/wp-content/themes/default');

1. WP_HOME and WP_SITEURL wp-config.php directvies

The WP_HOME and WP_SITEURL variables are used to hard-code the address of the wordpress blog or site url, so wordpress doesn't have to check everytime in the database on every user request to know it is own URL address.

2. TEMPLATEPATH and TEMPLATEPATH wp variables

This variables will surely improve performance to Wodpress blogs which doesn't implement caching. On wp install with enabled caching plugins like WordPress Super Cache, Hyper Cache or WordPress Db Cache is used, I don't know if this variables will have performance impact …

So far I have tested the vars on a couple of wordpress based installs with caching enabled and even on them it seems the pages load faster than before, but I cannot say this for sure as I did not check the site loading time in advance before hardcoding the vars.

Anyways even if the suggested variables couldn't make positive impact on performance, having the four variables in wp-config.php is a good practice for blogs or websites which are looking for extra clarity.
For multiple wordpress installations living on the same server, having defined the 4 vars in different wordpress seems like a good idea too.

How to install Microsoft Windows XP SP3 on Debian GNU / Linux Squeeze

Thursday, December 1st, 2011

Windows XP Service Pack 3 QEMU Debian Squeeze

I have never did a proper install of Windows XP on Debian before hand. Even though I experimented once long time ago. I had zero success with installing Windows XP Service Pack 2 . The only Windows I can make correctly working before hand on these early days on my Debian powered notebook with qemu virtual machine emulator was Windows 2000 .

I decided to give it another go today as I hoped the qemu has advanced and I’ve seen many reports online of people who were able to correctly make Windows XP SP2 work out.

As I’ve seen many blog posts online of people who succesfully run with qemu Windows XP SP2, in order to escape from repeating the other guys experience and conduct a fresh experiment, I decided to give qemu a try with Microsoft.Windows.XP.Professional.SP3.Integrated.June.2011.Corporate

Before I proceed with using latest qemu I,

1. Installed qemu using the usual:

debian:~# apt-get install --yes qemu qemu-keymaps qemu-system qemu-user qemu-utils uml-utilities
...

Afterwards,

2. Created a new directory where the qemu Windows image will be stored:

debian:~# su hipo
hipo@noah:~$ mkdir windows
hipo@noah:~$ cd windows
hipo@noah:/home/hipo/windows$

As a following step I loaded the tun kernel module which is necessery for Qemu to properly handle the Windows LAN networking.

3. Load and set proper permissions for tun kernel module

In case if /dev/net is not existing first step is to create the proper device, however in most cases /dev/net should be there:

debian:~# mkdir -p /dev/net
debian:~# mknod /dev/net/tun c 10 200

As a next step its necessery to load tun kernel module and set the proper permissions:

debian:~# modprobe tun
debian:~# echo 'tun' >> /etc/modules
debian:~# chgrp users /dev/net/tun
debian:~# chmod g+w /dev/net/tun

Next step is to create an image file with dd or with qemu-img which will be holding the Virtual Machine Windows installation.

4. Create image file for Windows using dd

I decided to create a the image file to be with a size of 5 Gigabytes, this is of course custom so other people might prefer having it less or more the absolute minimum for a proper Windows XP SP3 install is 2000 Megabytes.

debian:~# su hipo -; cd windows;
debian:/home/hipo/windows$ dd of=hd.img bs=1024 seek=5000000 count=0
0+0 records in
0+0 records out
0 bytes (0 B) copied, 1.5505e-05 s, 0.0 kB/s

Notice here that the file dd will create will appear like 0 kb file until the Windows install from a BootCD is run with qemu.

5. Download an image of Microsoft.Windows.XP.Professional.SP3.Integrated.June.2011.Corporate from thepiratebay.org

Microsoft.Windows.XP.Professional.SP3.Integrated.June.2011.Corporate is currently available for download from the thepiratebay.org if in the times to come it is not available it will most likely be available from torrentz.net, isohunt.com etc. so I’ll skip more explanations with this step and let you use your favourite torrent program of choice to download the MS Windows iso. Just to make a note here I used transmission as this is my favourite torrent client. After downloading the iso I used K3B to burn the Image file as Bootable ISO. I’m naturally a GNOME user so to burn it as Image I just open it with K3B by using the GNOME menu and selecting Open with K3B

Next I instructed qemu to boot from the just burnt CD.

6. Boot windows Installation with Qemu from the Boot CD

debian:/home/hipo/windows$ qemu -boot d -cdrom /dev/cdrom -hda hd.img

Notice here that I’m running the qemu virtual machine emulator with a non-privileged reasons. This is important as qemu might have holes in the emulation of Windows Networking stack which if executed as root superuser. Can allow some malicious attacker to remotely compromise your GNU / Linux PC …

Qemu window will pop-up where one installs the Windows as it will install it using an ordinary PC. To switch qemu to fullscreen mode to have the complete feeling like installing Windows on an non-emulated PC ctrl + alt + f can be pressed.

The Windows installation took like 1 hour 20 minutes on my dual core 1.8 Ghz notebook with 2 GB of RAM. But I should say while installing I had multiple applications running; xmms, transmission, epiphany, icedove, evince etc. probably if I just run the Virtual Machine with no other applications to extra load my PC, probably the Windows install would have been done in max 50 minutes time.

After the installation is complete. To

7. Further run the installed Windows debian:/home/hipo/windows$ qemu -hda hd.img -boot c
...

As a next step its necessery to;

8. Bring up the tap0 interface and configure it for the user

I’m running my qemu emulator with my user hipo , so I run cmds:

debian:/home/hipo/windows$ su - root
debian:~# tunctl -u hipo
Set 'tap0' persistent and owned by uid 1000

9. Enable ip_forwarding and arp proxy and for wlan0 and tap0

debian:~# echo 1 > /proc/sys/net/ipv4/conf/wlan0/proxy_arp
debian:~# echo 1 > /proc/sys/net/ipv4/conf/tap0/proxy_arp
debian:~# echo 1 > /proc/sys/net/ipv4/conf/tap0/proxy_arp

10. Install the proper Network Drivers inside Windows

That’s just in case, if they’re not supported by the Windows default existing drivers.
To do so, I downloaded my LAN drivers from the Vendor and put it on USB and sticked the USB drive to my laptop. In order to make the Kingston USB drive I used to transfer my LAN and Video drivers. I had to restart qemu with the parameter -usb -usbdevice host:0951:1625 , where I used lsusb to check and get the correct USB ID 0951:1625, like shown in the command below:

debian:~# lsusb |grep -i kingston
Bus 001 Device 006: ID 0951:1625 Kingston Technology DataTraveler 101 II

After on I booted again the Windows XP with the following command line in order to make qemu detect the USB Drive:

debian:/home/hipo/windows# sudo qemu -boot c -hda hd.img -usb -usbdevice host:0951:1625

One oddity here is that in order for qemu to detect the USB stick, I had to run it via sudo with super user privileges.Don’t ask me why this is the only way it worked …
Next on used the Windows device manager from Control Panel -> System -> Device Manager to point my undetected hardware to the correct Win drivers.

For the GUI preferring user qemu has a nice GNOME GUI interface called qemu-launcher, if you like to use qemu via it instead of scripting the qemu launcher commands, you can install and use via:

debian:~# apt-get install --yes qemu-launcher qemuctl
...
debian:/home/hipo/windows$ qemu-launcher

QEMU-Launcher Debian Squeeze Screenshot

Another GUI alternative to qemu-launcher, which easifys the work with qemu is qemulator; here is a screenshot:

Qemulator 0.5 - Qemu GUI Screenshot Debian Squeeze

Monitoring Windows hosts with Nagios on Debian GNU/Linux

Tuesday, August 30th, 2011

Nagios logo install and configure nagios to monitor Windows hosts with on Debian GNU/Linux

In this article in short, I’ll explain how I configured Nagios on a Debian GNU/Linux release (Squeeze 6) to monitor a couple of Windows hosts running inside a local network. Now let’s start.

1. Install necessery nagios debian packages

apt-get install nagios-images nagios-nrpe-plugin nagios-nrpe-server nagios-plugins nagios-plugins-basic nagios-plugins-standard
nagios3 nagios3-cgi nagios3-common nagios3-core

2. Edit /etc/nagios-plugins/config/nt.cfg

In the File substitute:

define command { command_name check_nt command_line /usr/lib/nagios/plugins/check_nt -H '$HOSTADDRESS$' -v '$ARG1$' }

With:

define command {
command_name check_nt
command_line /usr/lib/nagios/plugins/check_nt -H '$HOSTADDRESS$' -p 12489 -v $ARG1$ $ARG2$
}

3. Modify nrpe.cfg to put in allowd hoss to connect to the Nagions nrpe server

vim /etc/nagios/nrpe.cfg

Lookup inside for nagios’s configuration directive:

allowed_hosts=127.0.0.1

In order to allow more hosts to report to the nagios nrpe daemon, change the value to let’s say:

allowed_hosts=127.0.0.1,192.168.1.4,192.168.1.5,192.168.1.6

This config allows the three IPs 192.168.1.4-6 to be able to report for nrpe.

For the changes to nrpe server to take effect, it has to be restrarted.

debian:~# /etc/init.d/nagios-nrpe-server restart

Further on some configurations needs to be properly done on the nrpe agent Windows hosts in this case 192.168.1.4,192.168.1.5,192.168.1.6

4. Install the nsclient++ on all Windows hosts which CPU, Disk, Temperature and services has to be monitored

Download the agent from http://sourceforge.net/projects/nscplus and launch the installer, click twice on it and follow the installation screens. Its necessery that during installation the agent has the NRPE protocol enabled. After the installation is complete one needs to modify the NSC.ini
By default many of nsclient++ tracking modules are not enabled in NSC.ini, thus its necessery that the following DLLs get activated in the conf:

FileLogger.dll
CheckSystem.dll
CheckDisk.dll
NSClientListener.dll
SysTray.dll
CheckEventLog.dll
CheckHelpers.dll

Another requirement is to instruct the nsclient++ angent to have access to the Linux installed nagios server again with adding it to the allowed_hosts config variable:

allowed_hosts=192.168.1.1

In my case the Nagios runs on Debian Lenny (Squeeze) 6 and possess the IP address of 192.168.1.1
To test the intalled windows nsclient++ agents are properly installed a simple telnet connection from the Linux host is enough:

5. Create necessery configuration for the nagios Linux server to include all the Windows hosts which will be monitored

There is a window.cfg template file located in /usr/share/doc/nagios3-common/examples/template-object/windows.cfg on Debian.

The file is a good start point for creating a conf file to be understand by nagios and used to periodically refresh information about the status of the Windows hosts.

Thus it’s a good idea to copy the file to nagios3 config directory:

debian:~# mkdir /etc/nagios3/objects
debian:~# cp -rpf /usr/share/doc/nagios3-common/examples/template-object/windows.cfg /etc/nagios3/objects/windows.cfg

A sample windows.cfg content, (which works for me fine) and monitor a couple of Windows nodes running MS-SQL service and IIS and makes sure the services are up and running are:

define host{
use windows-server ; Inherit default values from a template
host_name Windows1 ; The name we're giving to this host
alias Iready Server ; A longer name associated with the host
address 192.168.1.4 ; IP address of the host
}
define host{
use windows-server ; Inherit default values from a template
host_name Windows2 ; The name we're giving to this host
alias Iready Server ; A longer name associated with the host
address 192.168.1.4 ; IP address of the host
}
define hostgroup{
hostgroup_name windows-servers ; The name of the hostgroup
alias Windows Servers ; Long name of the group
}
define hostgroup{
hostgroup_name IIS
alias IIS Servers
members Windows1,Windows2
}
define hostgroup{
hostgroup_name MSSQL
alias MSSQL Servers
members Windows1,Windows2
}
define service{
use generic-service
host_name Windows1
service_description NSClient++ Version
check_command check_nt!CLIENTVERSION
}
define service{ use generic-service
host_name Windows1
service_description Uptime
check_command check_nt!UPTIME
}
define service{ use generic-service
host_name Windows1
service_description CPU Load
check_command check_nt!CPULOAD!-l 5,80,90
}
define service{
use generic-service
host_name Windows1
service_description Memory Usage
check_command check_nt!MEMUSE!-w 80 -c 90
define service{
use generic-service
host_name Windows1
service_description C: Drive Space
check_command check_nt!USEDDISKSPACE!-l c -w 80 -c 90
}
define service{
use generic-service
host_name Windows1
service_description W3SVC
check_command check_nt!SERVICESTATE!-d SHOWALL -l W3SVC
}
define service{
use generic-service
host_name Windows1
service_description Explorer
check_command check_nt!PROCSTATE!-d SHOWALL -l Explorer.exe
}
define service{
use generic-service
host_name Windows2
service_description NSClient++ Version
check_command check_nt!CLIENTVERSION
}
define service{ use generic-service
host_name Windows2
service_description Uptime
check_command check_nt!UPTIME
}
define service{ use generic-service
host_name Windows2
service_description CPU Load
check_command check_nt!CPULOAD!-l 5,80,90
}
define service{
use generic-service
host_name Windows2
service_description Memory Usage
check_command check_nt!MEMUSE!-w 80 -c 90
define service{
use generic-service
host_name Windows2
service_description C: Drive Space
check_command check_nt!USEDDISKSPACE!-l c -w 80 -c 90
}
define service{
use generic-service
host_name Windows2
service_description W3SVC
check_command check_nt!SERVICESTATE!-d SHOWALL -l W3SVC
}
define service{
use generic-service
host_name Windows2
service_description Explorer
check_command check_nt!PROCSTATE!-d SHOWALL -l Explorer.exe
}
define service{ use generic-service
host_name Windows1
service_description SQL port Check
check_command check_tcp!1433
}
define service{
use generic-service
host_name Windows2
service_description SQL port Check
check_command check_tcp!1433
}
The above config, can easily be extended for more hosts, or if necessery easily setup to track more services in nagios web frontend.
6. Test if connectivity to the nsclient++ agent port is available from the Linux server

debian:~# telnet 192.168.58.6 12489
Trying 192.168.58.6...
Connected to 192.168.58.6.
Escape character is '^]'.
asd
ERROR: Invalid password.

Another good idea is to launch on the Windows host the NSClient++ (system tray) , e.g.:

Start, All Programs, NSClient++, Start NSClient++ (system tray).

Test Nagios configuration from the Linux host running nagios and nrpe daemons to check if the check_nt, can succesfully authenticate and retrieve data generated from the nsclient++ on the Windows host:

debian:~# /usr/lib/nagios/plugins/check_nt -H 192.168.1.5 -p 12489 -v CPULOAD -w 80 -c 90 -l 5,80,90,10,80,90

If everything is okay and the remote Windows system 192.168.1.5 has properly configured and running NSClient++ the above command should return an output like:

CPU Load 1% (5 min average) 1% (10 min average) | '5 min avg Load'=1%;80;90;0;100 '10 min avg Load'=1%;80;90;0;100

In case of the command returns:

could not fetch information from server

instead this means that probably there is some kind of problem with authentication or handshake of the Linux host’s nagios check_nt to the Windows server’s running on 12489.

This is sometimes caused by misconfigured NSC.ini file, however in other occasions this error is caused by misconfigured Windows Firewall or because the NSClient++ is not running with Administrator user.

By the way important note to make about Windows 2008r2 is that if NSClient++ is running there it’s absolutely required to Login with Windows Administrator and run the NSClient++ /start , if it’s run through the Run As Adminsitrator with an admin privileged user the aforementioned error might appear, so be careful.
I’ve experienced this error myself and it took me about 40 minutes to find that I have to run it directly with Administrator user after logging as Administrator.

7. Create nagios web iface Apache configuration

nagios debian pachage is shipped with a config which is suitable to be set debian:~# cp -rpf /usr/share/doc/nagios3-common/examples/apache2.conf /etc/apache2/sites-avalable/nagios
debian:~# ln -sf /etc/apache2/sites-available/nagios /etc/apache2/sites-enabled/nagios

The /etc/apache2/sites-available/nagios can easily be configured to work on Virtualhost, to do so the above copied file need to be wrapped inside a VirtualHost directive. For that put in the beginning of the file;

<VirtualHost *:80>

and in the end of the file:

<VirtualHost *:80>

8. Restart nagios server and Apache for the new settings to take effect

debian:~# /etc/init.d/apache2 restart
...
debian:~# /etc/init.d/nagios3 restart

If some custom configuration about tracking the Debian Linux nagios host running services needs to be made, its also helpful for one to check in /etc/nagios3/conf.d

Well that’s mostly what I had to do to make the Nagios3 server to keep track of a small Windows network on Debian GNU/Linux Squeeze 6, hope this small article helps. Cheers 😉

How to install Nvidia GeForce FX 5500 on Ubuntu 11.04

Tuesday, July 19th, 2011

Nvidia Tux GeForce GNU / Linux

Yesterday I was at a friend of mine who has recently installed Ubuntu 11.04 to his already oldish Desktop computer.

The system was 1.4Ghz (amd) with 512 RAM and some kind of Dell Trinitron 19 inch monitor
Even though he tried hard to make his NVIDIA GeForce FX 5500 ‘s drive to work properly with Ubuntu Natty Narwhal, he just has messed it even more.
As I always like helping people and I’m joyful for people who want to migrate to Linux, I took some time to make his NVIDIA GeForce work with this Ubuntu release.

First I tried to make it work by using some of the official NVIDIA Linux drivers located on nvidia.com following some online tutorial for Ubuntu claiming that it works but actually it didn’t, so finally after a bit of experimentation I found a way to make this video card work.
Here is how:

1. Install the following Ubuntu packages

root@ubuntu:~# apt-get install nouveau-firmware nvidia-173 nvidia-173-kernel-source
nvidia-cg-toolkit nvidia-common nvidia-current nvidia-glx-173 nvidia-settings
...

2. Load in the kernel and set to be auto loaded on boot nvidia’s driver kernel module nvidia-173

root@ubuntu:~# depmod -a;
root@ubutnu:~# modprobe nvidia-173
root@ubuntu:~# echo nvidia-173 >> /etc/modules

3. Stop temporary (Gnome dipsplay manager) gdm

root@ubuntu:~# service gdm stop
...

4. Use nvidia-xconfig to generate a working version of /etc/X11/xorg.conf for Nvidia

root@ubuntu:~# nvidia-xconfig
..

nvidia-xconfig will generate new /etc/X11/xorg.conf configuration corresponding to the Nvidia GeForce Fx 5500 and will move the old xorg.conf to xorg.conf.backup.

5. Start the gdm manager to be running again

root@ubuntu:~# service gdm start
...

Now the Xserver will start in a terrible mode of 640×480, probably because Ubuntu was unable to define correct VerticalSync and HorizontalSync for the 19 inch Dell Trinitron monitor or for some other weird reason, to fix this it’s quite easy though.
The fix to the NVIDIA GeForce 5500 running in 640×480 mode is done straigh via Gnome menus.

6. Use Gnome’s System -> Preferences -> Monitors to set raise up the Xserver resolution

Navigate to Gnome’s menus:

System -> Preferences -> Monitors

Gnome System Preferences Monitors Nvidia GeForce 5500 Ubuntu

Here you will have to select more appropriate resolution and a different refresh rate, which in my case was 1024×768 and further on to store the settings press the Apply button.

One oddity here was that according to the Monitor Preferences the refresh rate was running on 54 Hz which I don’t believe was the case as I guess it’s some kind of Gnome or Ubuntu bug. I changed the 54 Hz Refresh Rate to 50 Hz as using the 54 Hz refresh rate as the screen had a minor vibrations observable if one takes a thorough look on the screen.

Setting the NVIDIA GeForce 5500 driver to work with 50 Hz Refresh Rate in Gnome loooked like the Windows’s 85 Hz RR and looked quite nice so I left it this way.

Finally to test the newly installed driver 3D acceleration I used glxgears.

7. Install glxgears in order to be able to test that 3D acceleration on Nvidia works fine

root@ubuntu:~# apt-get install mesa-utils

After installing mesa-utils which nowdays contains glxgears executable one needs to execute the glxgears binary.

root@ubuntu:~# glxgears

Immediately after a window containing the glxgears should popup on the screen, like shown in below screenshot
Benchmark 3d Acceleration Linu glxgears

glxgears showed 3d acceleration works fine as the performance for 3d rendering shown was quite good and therefore 3D acceleration was running fine.

And that was it now the video works like and my friends, can enjoy the fun to have a generally virus Free OS 😉