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h1. Debian 11 to 12

h2. Pre update check

h3. Stretch check

Check if any sources still point to buster

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

If so, bring those up to bullseye and run updates first
https://redmine.palantetech.coop/projects/commons/wiki/Debian_10_to_11

h3. Metapackage check

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

<pre>
dpkg -l "linux-image*" | grep ^ii | grep -i meta
</pre> 

should have results

If not, install metapackage
https://www.debian.org/releases/bookworm/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/bookworm/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>


h3. Update sources list

Check which sources exist that point to bullseye

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

Edit the main list, and any others that come up

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

replace bullseye with bookworm

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


*Good to check but should be done if upgraded from Debian 10 to 11*
replace bullseye/updates with bookworm-security
<pre>
:%s/bookworm\/updates/bookworm-security/g
</pre>

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

h2. Upgrade the system

h3. Update the sources

<pre>
apt-get update
</pre>

h3. Check for Necessary Disk Space

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


Change configs during full upgrade?
|package | change configs|
| nrpe | no |
| sudoers | no |
| journald | no |
| backupninja | no |
| nginx | yes but recheck after |
| redis | yes but recheck after |
| sshd_config | yes but recheck after |
| glibc | yes |
| logrotate.d/apache2 | yes |

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

<pre>
mysql_upgrade
</pre>


h2. Validation Testing and Auditing Changes

    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 entry for that server to make sure everything has recovered

h3. Check what packages were removed

<pre>
    cat /var/log/apt/history.log | grep Remove
</pre>
    copy that into ongoing updates documentation for records
    Make sure there was nothing important in there
    If there were important packages in there

* check aptitude to see if newer versions were already installed
* check debian package search to search for what version is appropriate (https://packages.debian.org/)


h2. Common problems


h3. NO_PUBKEY during update

When issues are encountered they should be listed here to ease future troubleshooting!

h3. Backupninja changes

After update, backupninja likely needs to be patched
https://redmine.palantetech.coop/projects/pt/wiki/Icinga2#Patch-the-backupninja-binary

Borg backup jobs to May First need to have port = 2201 added to the destination section.