Linstor DRBD on Proxmox Backup Server

I knew about rmmod drbd and modprobe drbd but it didn’t work this time, weird.

I don’t know if it’s because I tried to apt install pve-headers-$(uname -r) on the PBS, then apt -y install --reinstall drbd-dkms drbd-utils and finally another rmmod drbd ; modprobe drbd and it worked :
version: 9.2.14 (api:2/proto:118-123)
GIT-hash: a1e7c10e591a844b327da120d169df7da7c933b7 build by root@backup, 2025-07-29 13:38:40
Transports (api:21): tcp (9.2.14)

I will probably reinstall the nodes cleanly later as this is just some tests to get everything working as intended.
I’m kinda worried about the PBS showing a “pve” kernel now :
uname -r -> 6.8.12-12-pve or was it always the case ?

After a little check on the actual kernel on my other PBS node, which is 100% alone from PVE environment, is also a “pve” one :
6.8.12-11-pve
I’m kinda relieved that it’s normal and they are just shipping “-pve” named kernel for PBS.

Regarding the linstor cluster ; after deleting everything old with linstor commands (nodes, resource-definition, resource-group…), I created the cluster again and now the PBS backup node is able to DRBD and in fact Tie-Breaking with my test resource :

╭────────────────────────────────────────────────────────────────────────╮
┊ Node   ┊ DRBD ┊ LUKS ┊ NVMe ┊ Cache ┊ BCache ┊ WriteCache ┊ Storage ┊
╞════════════════════════════════════════════════════════════════════════╡
┊ backup ┊ +    ┊ -    ┊ +    ┊ +     ┊ -      ┊ +          ┊ +       ┊
┊ srv1   ┊ +    ┊ -    ┊ +    ┊ +     ┊ -      ┊ +          ┊ +       ┊
┊ srv2   ┊ +    ┊ -    ┊ +    ┊ +     ┊ -      ┊ +          ┊ +       ┊
╰────────────────────────────────────────────────────────────────────────╯
root@backup:~# linstor r l
╭─────────────────────────────────────────────────────────────────────────────────────────────╮
┊ ResourceName ┊ Node   ┊ Layers       ┊ Usage  ┊ Conns ┊      State ┊ CreatedOn           ┊
╞═════════════════════════════════════════════════════════════════════════════════════════════╡
┊ pm-61dae041  ┊ backup ┊ DRBD,STORAGE ┊ Unused ┊ Ok    ┊ TieBreaker ┊ 2025-07-29 14:32:32 ┊
┊ pm-61dae041  ┊ srv1   ┊ DRBD,STORAGE ┊ Unused ┊ Ok    ┊   UpToDate ┊ 2025-07-29 14:32:32 ┊
┊ pm-61dae041  ┊ srv2   ┊ DRBD,STORAGE ┊ Unused ┊ Ok    ┊   UpToDate ┊ 2025-07-29 14:32:33 ┊
┊ pm-d2da2116  ┊ backup ┊ DRBD,STORAGE ┊ Unused ┊ Ok    ┊ TieBreaker ┊ 2025-07-29 14:32:26 ┊
┊ pm-d2da2116  ┊ srv1   ┊ DRBD,STORAGE ┊ Unused ┊ Ok    ┊   UpToDate ┊ 2025-07-29 14:32:26 ┊
┊ pm-d2da2116  ┊ srv2   ┊ DRBD,STORAGE ┊ Unused ┊ Ok    ┊   UpToDate ┊ 2025-07-29 14:32:27 ┊
┊ pm-fa6753cf  ┊ backup ┊ DRBD,STORAGE ┊ Unused ┊ Ok    ┊ TieBreaker ┊ 2025-07-29 14:32:29 ┊
┊ pm-fa6753cf  ┊ srv1   ┊ DRBD,STORAGE ┊ Unused ┊ Ok    ┊   UpToDate ┊ 2025-07-29 14:32:29 ┊
┊ pm-fa6753cf  ┊ srv2   ┊ DRBD,STORAGE ┊ Unused ┊ Ok    ┊   UpToDate ┊ 2025-07-29 14:32:30 ┊
╰─────────────────────────────────────────────────────────────────────────────────────────────╯

As we can see, the backup node also created the resource files (1 resource per Windows VM disk):

root@backup:~# ls -la /var/lib/linstor.d/
total 24
drwxr-xr-x  3 root root 4096 Jul 29 14:32 .
drwxr-xr-x 33 root root 4096 Jul 29 12:15 ..
drwxr-xr-x  2 root root 4096 Jul 29 14:32 .backup
-rw-r--r--  1 root root    0 Jul 29 14:32 loop_device_mapping
-rw-r--r--  1 root root 2010 Jul 29 14:32 pm-61dae041.res
-rw-r--r--  1 root root 2010 Jul 29 14:32 pm-d2da2116.res
-rw-r--r--  1 root root 2010 Jul 29 14:32 pm-fa6753cf.res

root@backup:~# ls -la /var/lib/linstor.d/.backup
total 20
drwxr-xr-x 2 root root 4096 Jul 29 14:32 .
drwxr-xr-x 3 root root 4096 Jul 29 14:32 ..
-rw-r--r-- 1 root root 2010 Jul 29 14:32 pm-61dae041.res
-rw-r--r-- 1 root root 2010 Jul 29 14:32 pm-d2da2116.res
-rw-r--r-- 1 root root 2010 Jul 29 14:32 pm-fa6753cf.res