* When install reaches partitioning step, select "manual", format the 40G partition asext4, set mountpoint as `/`
** Partitioner should wipe `/` and `swap`. Anything else, you done fucked up.
* [[Tendril doesn't like this in-place upgrade, so it requires a disable + drop + add + enable after upgrade, otherwise the Act. (last contact) field doesn't get updated.|[https://wikitech.wikimedia.org/wiki/MariaDB#Stretch_+_10.1_-%3E_Buster_+_10.4_known_issues]]
** Check out [[tendril repo|https://gerrit.wikimedia.org/r/#/admin/projects/operations/software/tendril]] on a cumin host. (Use http, as you don't have your ssh key available).
** Remove host from tendril:<div>
```
./tendril-host-drop.sh HOST PORT | sudo -i mysql -h db1115.eqiad.wmnet tendril
```
</div>
** After, re-add host to tendril:<div>
```
./tendril-host-add.sh HOST PORT ~/.my.cnf.tendril tendril | sudo -i mysql -h db1115.eqiad.wmnet tendril
./tendril-host-enable.sh HOST PORT | sudo -i mysql -h db1115.eqiad.wmnet tendril
```
</div>
* Wait for host to finish reimaging
* Check that wmf-mariadb104 is installed.
* Re-add `/srv` to `/etc/fstab`
* Mount `/srv`
* Check if the contents of `/srv` are already owned by the `mysql` user, if not, fix.
* Disable replication while we run `mysql_upgrade`: ` systemctl set-environment MYSQLD_OPTS="--skip-slave-start"`
** Does not need to be reverted.
* Start mariadb: `systemctl start mariadb`
* Check service logs: `journalctl -xe -u mariadb`, should only see errors about internal tables that will be fixed by `mysql_upgrade`