Posts Tagged ‘Reboot’

Upgrade Debian Linux 9 to 10 Stretch to Buster and Disable graphical service load boot on Debian 10 Linux / Debian Buster is out

Tuesday, July 9th, 2019

howto-upgrade-debian-linux-debian-stretch-to-buster-debian-10-buster

I've just took a time to upgrade my Debian 9 Stretch Linux to Debian Buster on my old school Laptop (that turned 11 years old) Lenovo Thinkpad R61 . The upgrade went more or less without severe issues except few things.

The overall procedure followed is described n a few websites out there already and comes up to;

 

0. Set the proper repository location in /etc/apt/sources.list


Before update the sources.list used are:
 

deb [arch=amd64,i386] http://ftp.bg.debian.org/debian/ buster main contrib non-free
deb-src [arch=amd64,i386] http://ftp.bg.debian.org/debian/ buster main contrib non-free

 

deb [arch=amd64,i386] http://security.debian.org/ buster/updates main contrib non-free
deb-src [arch=amd64,i386] http://security.debian.org/ buster/updates main contrib non-free

deb [arch=amd64,i386] http://ftp.bg.debian.org/debian/ buster-updates main contrib non-free
deb-src [arch=amd64,i386] http://ftp.bg.debian.org/debian/ buster-updates main contrib non-free

deb http://ftp.debian.org/debian buster-backports main


For people that had stretch defined in /etc/apt/sources.list you should change them to buster or stable, easiest and quickest way to omit editting with vim / nano etc. is run as root or via sudo:
 

sed -i 's/stretch/buster/g' /etc/apt/sources.list
sed -i 's/stretch/buster/g' /etc/apt/sources.list.d/*.list

The minimum of config in sources.list after the modification should be
 

deb http://deb.debian.org/debian buster main
deb http://deb.debian.org/debian buster-updates main
deb http://security.debian.org/debian-security buster/updates main

Or if you want to always be with latest stable packages (which is my practice for notebooks):

deb http://deb.debian.org/debian stable main
deb http://deb.debian.org/debian stable-updates main
deb http://security.debian.org/debian-security stable/updates main

 

1. Getting list of hold packages if such exist and unholding them, e.g.

 

apt-mark showhold


Same could also be done via dpkg

dpkg –get-selections | grep hold


To unhold a package if such is found:

echo "package_name install"|sudo dpkg –set-selections

For those who don't know what hold package is this is usually package you want to keep at certain version all the time even though after running apt-get upgrade to get the latest package versions.
 

2. Use df -h and assure you have at least 5 – 10 GB free space on root directory / before proceed

df -h /

3. Update packages list to set new set repos as default

apt update

 

4. apt upgrade
 

apt upgrade

Here some 10 – 15 times you have to confirm what you want to do with configuration that has changed if you're unsure about the config (and it is not critical service) you're aware as such as Apache / MySQL / SMTP etc. it is best to install the latest maintainer version.

Hopefully here you will not get fatal errors that will interrupt it.

P.S. It is best to run apt-update either in VTTY (Virtual console session) with screen or tmux or via a physical tty (if this is not a remote server) as during the updates your GUI access to the gnome-terminal or konsole / xterm whatever console used might get cut. Thus it is best to do it with command:
 

screen apt upgrade

 

5. Run dist-upgrade to finalize the upgrade from Stertch to Buster

 

Once all is completed of the new installed packages, you will need to finally do, once again it is best to run via screen, if you don't have installed screen install it:

 

if [ $(which screen) ]; then echo 'Installed'; else apt-get install –yes screen ; fi

screen apt dist-upgrade


Here once again you should set whether old configuration to some e services has to stay or the new Debian maintainer package shipped one will overwrite the old and locally modified (due to some reason), here do wisely whatever you will otherwise some configured services might not boot as expected on next boot.

 

6. What if you get packages failed on update


If you get a certain package failed to configure after installed due to some reason, if it is a systemd service use:

 

journalctl -xe |head -n 50


or fully observer output of journalctl -xe and decide on yourself.

In most cases

dpkg-reconfigure failed-package-name


should do the trick or at least give you more hints on how to solve it.

 

Also if a package seems to be in inconsistent or broken state after upgrade  and simple dpkg-reconfigure doesn't help, a good command
that can help you is

 

dpkg-reconfigure -f package_name

 

or you can try to workaround a failed package setup with:
 

dpkg –configure -a

 
If dpkg-reconfigure doesn't help either as I experienced in prior of Debian from Debian 6 -> 7 an Debian 7 ->8 updates on some Computers, then a very useful thing to try is:
 

apt-get update –fix-missing 

apt-get install -f


At certain cases the only work around to be able to complete the package upgrade is to to remove the package with apt remove but due to config errors even that is not possible to work around this as final resort run:
 

dpkg –remove –force-remove-reinstreq

 

7. Clean up ununeeded packages

 

Some packages are left over due to package dependencies from Stretch and not needed in buster anymore to remove them.
 

apt autoremove

 

8. Reboot system once all upgrade is over

 

/sbin/reboot

 

9. Verify your just upgraded Debian is in a good state

 

root@noah:~# uname -a;
Linux noah 4.19.0-5-rt-amd64 #1 SMP PREEMPT RT Debian 4.19.37-5 (2019-06-19) x86_64 GNU/Linux

 

root@noah:~# cat /etc/issue.net
Debian GNU/Linux 10
 

 

root@noah:~# lsb_release -a
No LSB modules are available.
Distributor ID:    Debian
Description:    Debian GNU/Linux 10 (buster)
Release:    10
Codename:    buster

 

root@noah:~# hostnamectl
   Static hostname: noah
         Icon name: computer-laptop
           Chassis: laptop
        Machine ID: 4759d9c2f20265938692146351a07929
           Boot ID: 256eb64ffa5e413b8f959f7ef43d919f
  Operating System: Debian GNU/Linux 10 (buster)
            Kernel: Linux 4.19.0-5-rt-amd64
      Architecture: x86-64

 

10. Remove annoying picture short animation with debian logo looping

 

plymouth-debian-graphical-boot-services

By default Debian 10 boots up with annoying screen hiding all the status of loaded services state .e.g. you cannot see the services that shows in [ FAILED ] state and  which do show as [ OK ] to revert back the old behavior I'm used to for historical reasons and as it shows a lot of good Boot time debugging info, in previous Debian distributions this was possible  by setting the right configuration options in /etc/default/grub

which so far in my config was like so

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash scsi_mod.use_blk_mq=y dm_mod.use_blk_mq=y zswap.enabled=1 text"


Note that zswap.enabled=1 passed option is because my notebook is pretty old machine from 2008 with 4GB of memory and zswap does accelerate performance when working with swap – especially helpful on Older PCs for more you can read more about zswap on ArchLinux wiki
After modifying this configuration to load the new config into grub the cmd is:
 

/usr/sbin/update-grub

 
As this was not working and tried number of reboots finally I found that annoying animated gif like picture shown up is caused by plymouth below is excerpts from Plymouth's manual page:


       "The plymouth sends commands to a running plymouthd. This is used during the boot process to control the display of the graphical boot splash."

Plymouth has a set of themes one can set:

 

# plymouth-set-default-theme -l
futureprototype
details
futureprototype
joy
lines
moonlight
softwaves
spacefun
text
tribar

 

I tried to change that theme to make the boot process as text boot as I'm used to historically with cmd:
 

update-alternatives –config text.plymouth

 
As after reboot I hoped the PC will start booting in text but this does not happened so the final fix to turn back to textmode service boot was to completely remove plymouth
 

apt-get remove –yes plymouth

Umounting Linux drive if it doesn’t want to unmount “umount: /media/cdrom: device is busy”

Thursday, September 26th, 2013

If you use Linux as Desktop or even on some servers you might end up in situation where mounted filesystem is refusing to unmount with an error:
 

umount: /media/cdrom: device is busy

That's pretty annoying and many people (especially) desktop users would force a system reboot in order to have the fs unmounted.

If this happened to you, there is no need for that anymore. umount cmd has a handy option – (Lazy Unmount) for situations like this. Here is -l description from umount manual:

 -l     Lazy unmount. Detach the filesystem from the filesystem hierarchy now, and cleanup all references to the filesystem as soon
              as it is not busy anymore.  (Requires kernel 2.4.11 or later.)

So next time you hit "umount device is busy" do:

# umount -l /media/cdrom

Enjoy 😉

Solve ALSA audio and mic issues on Lenovo Thinkpads on Debian and Ubuntu Linux

Wednesday, January 11th, 2012

Since I've blogged about my recent skype issues. I've played a lot with pulseaudio, alsa, alsa-oss to experimented a lot until I figured out why Skype was failing to properly delivery sound and record via my embedded laptop mic.

Anyways, while researching on the cause of my Thinkpad r61 mic issues, I've red a bunch of blog posts by people experiencing microphone oddities with Lenovo Thinkpads

Throughout the search I come across one very good article, which explained that in many cases the Thinkpad sound problems are caused by the snd-hda-intel alsa kernel module. snd-hda-intel fails to automatically set proper sb model type argument during Linux install when the soundcard is initialized with some argument like options snd-hda-intel model=auto

Hence, the suggested fix which should resolve this on many Thinkpad notebooks is up to passing the right module argument:

To fix its neceessery to edit /etc/modprobe.d/alsa-base.conf .

debian:~# vim /etc/modprobe.d/alsa-base.conf

Find the line in the file starting with:
options snd-hda-intel model=

and substitute with:

options snd-hda-intel model=thinkpad

Finally a restart of Advaned Linux Sound Architecture (alsa) is required:

debian:~# /etc/init.d/alsa restart
...

At most cases just restarting the alsa via its init script is not enough, since the ssnd-hda-intel kernel module is already in use by some program or something, so its best to do a reboot to make sure the module is loaded with the new model=thinkpad argument.

My exact laptop sound card model is:

debian:~# lspci |grep -i audio
00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03)

After changing the module and using alsamixer and aumix to make sure mic is unmuted and its volume is high enough, mic sound rec works fine.

Reboot Safely a frozen (hanged up) Linux Server with Magic SysRQ Key combination

Monday, June 20th, 2011

Linux Magic SysRQ Key picture

Being a remote system administrator for many years from now, I’ve experienced many times sudden Linux crashes, mostly caused by system hardware overloads.

This is a common thing especially on busy Web Servers with (Apache/MySQL). Situations like this are really messy and many times in order to bringt the server back online, one has to either physically go to the Data Center or contact the Technical support to request a server reboot.

In this terrible times, data loss might occur if the Server reset button is used to cold reboot it.

Happily in 99% of the cases the data loss which might occur could be prevented with Linux’s kernel capability to support the Magic SysRQ key !

Having the Magic SysRQ key functionality being supported in Linux in past times wasn’t that common, thanksfully these days this has changed andlmost every Linux distrubution supports this handy feature.

Now you might wonder what is the magic with those Magic SysRQ key ?

Let me explain, Magic SysRQ is a kernel level functionality which supports even completely crashed Linux systems with the horrifying:

Kernel Panic
message to be properly shutdown.

Using Magic SysRQ instead of the mostly used indiced cold reboots is really advantageous, as all the opened files by programs on the crashed server which hanged will be properly saved and closed and thus possible data loss caused by the sudden server crash will be minimized.

One other good thing about the Magic SysRQ Key keyboard combination is that initiating the Magic SysRQ could be made blindly (no need for server monitor or display to present any error messages on the failed server).

Now to check if the magic sysrq is enabled on a server one should issue the command:

Here are some Magic SysRQ keyboard combinations one can use in case of server failure:

ALT+SYSRQ+M to dump memory info;
ALT+SYSRQ+P to dump processes states;
ALT+SYSRQ+S to sync disks;
ALT+SYSRQ+U to unmount all mounted filesystems;
ALT+SYSRQ+E to terminate processes;
ALT+SYSRQ+I to kill all processes
ALT+SYSRQ+U to try to unmount once again;
ALT+SYSRQ+B to reboot.

I would skip to explain what each of the keyboard combinations will do as I believe the above description explains it well.

One classics of combinations one might want to issue on a failed Linux server supporting the Magic SysRQ would be:

ALT+SYSRQ+R
ALT+SYSRQ+E
ALT+SYSRQ+I
ALT+SYSRQ+S
ALT+SYSRQ+U
ALT+SYSRQ+B

The ALT+SYSRQ+REISUB key combination is very popular among system administrators.
Also Magic SysRQ is heavily used by kernel developers as it includes many handy debugging options.

If you try the Magic SysRQ key on older servers and you realize it doesn’t react you will have to recompile the linux kernel and enable the CONFIG_MAGIC_SYSRQ kernel time compilation option.

The Magic SysRQ can also be initiated remotely on a properly running server 😉 by initiating:

server:~# echo b > /proc/sysrq-trigger

This command would be useful if you want to just have fun and test that magic sysrq works on your system for sure 😉

To sum it up using the Magic SysRQ will guarantee your locked up, server a Safe Reboot and will hopefully save you a lot of time for backups recovery.

Blah Blah

Tuesday, February 27th, 2007

It was really steressing day. All started with a lot of calls to NetInfo’s Office then to our Office in Varna to explain what is happening to one of our servers design-bg.net. In the end after 2 hours of stress and even more everything come on it’s place Praise the LORD for this he helped me. Right after design-bg.net was up mail.design.bg almost freeze with God’s help everything came to normal after a simple reboot. In 12:00 to 12:40 I drunk coffee with some friends, after that spent some time in the library. In 14:15 the management test seemed to be in a small room and I was able to copy stuff from my collegues on the test:] Yeash CopyCat :]. Mitko and Habib was my guests today and we ate spinach’s soup with green salad and plant yellow cheese. Thanks to the Lord for being merciful over my sins. Yesterday I got drunk I drunk 200 gr. of ROM and 1 beer. After that I went home singing and listening to Metallica’s songs simultaneously, there was odd movement red eyes and head banging for almost an hour :]. I spend so many things for absolutely useless things, I am ashamed of myself. I acted like an animal. I really wonder why the world still exists If it’s such an awful place to be. I really doubt about the meaning of my life. Things seems to go in a bad way for me and a lot of ppl around me. I really hope the Lord will interfere and everything will come to place but who knows the Paths the Creator has created for us? END—–