{{lastupdated_at}} by {{lastupdated_by}}

{{>toc}}

h1. Debian 10 to 11

h2. Pre update check

h3. Stretch check

Check if any sources still point to stretch

<pre>
cd /etc/apt
grep -nr stretch .
</pre>

If so, bring those up to buster and run updates first
https://redmine.palantetech.coop/projects/commons/wiki/Debian_9_to_10

h3. Metapackage check

Check to make sure kernel metapackage is installed, not just specific kernel

@dpkg -l "linux-image*" | grep ^ii | grep -i meta@ should have results
If not, install metapackage
https://www.debian.org/releases/bullseye/amd64/release-notes/ch-upgrading.en.html#kernel-metapackage

h3. Purged package check

List and purge removed packages with config files remaining
https://www.debian.org/releases/bullseye/amd64/release-notes/ch-upgrading.en.html#purge-removed-packages

<pre>
aptitude search '~c'
aptitude purge '~c'
</pre>

h3. Hold check

These commands should have no results

<pre>
aptitude search "~ahold" 
dpkg --get-selections | grep 'hold$'
</pre>

h2. Update sources list

Check which sources exist that point to buster
<pre>
cd /etc/apt
grep -nr buster .
</pre>

Edit the main list, and any others that come up

<pre>
vim /etc/apt/sources.list
</pre>

replace buster with bullseye

<pre>
:%s/buster/bullseye/g
</pre>

replace bullseye/updates with bullseye-security

<pre>
:%s/bullseye\/updates/bullseye-security/g
</pre>

https://www.debian.org/releases/bullseye/amd64/release-notes/ch-information.en.html#security-archive

h2. Upgrade the system

h3. Check for Necessary Disk Space

<pre>apt-get -o APT::Get::Trivial-Only=true dist-upgrade</pre>

h3. Update the sources

<pre>
apt-get update
</pre>

h3. Minimal Upgrade

<pre> apt-get upgrade</pre>

* if it asks whether to change /etc/apt/trusted.gpg.d/debian-archive-jessie-security-automatic.gpg, say yes
* other things it asks to change, say no, keep the existing file

h3. Full Upgrade

<pre>
apt-get dist-upgrade
</pre>

h3. Upgrade MySQL databases (if MySQL/MariaDB installed)

<pre>
mysql_upgrade
</pre>

h3. Check that things are up

* if a web server, make sure websites are up
* if an infrastructure server, test and make sure all parts of the infrastructure are working properly
* if a PTC server check the "recovery plan":https://redmine.palantetech.coop/projects/pt/wiki/Recovery_Plan entry for that server to make sure everything has recovered

h3. Check what packages were removed

* @cat /var/log/apt/history.log | grep Remove@
* make sure there was nothing important in there


h2. Common problems

tbd