Portal:Cloud VPS/Admin/Runbooks/DRBDOnlyOnePrimary

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Overview

The procedures in this runbook require admin permissions to complete.

Error / Incident

There seems to be 0 or more than 1 DRBD primaries, that might mean many things:

  • If there's 0 primaries -> the cluster is not working, and one of the nodes might have to be forced to become primary
  • If there's >1 primaries -> there's a split brain, one of the nodes should be stopped and rejoined as secondary

Debugging

You can go to both of the nodes and see the current drbd status by running:

root@labstore1005:~# cat /proc/drbd
version: 8.4.7 (api:1/proto:86-101)
srcversion: F7D2F0C9036CD0E796D5958

1: cs:Connected ro:Secondary/Primary ds:UpToDate/UpToDate B r-----
   ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:0

3: cs:Connected ro:Secondary/Primary ds:UpToDate/UpToDate B r-----
   ns:0 nr:385762660 dw:385762660 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:0
4: cs:Connected ro:Secondary/Primary ds:UpToDate/UpToDate B r-----
   ns:0 nr:1229421488 dw:1229421488 dr:1471404 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:0

This is how it should look if it runs ok, you can see that there's 3 drbd resources, all connected, for with this node is Secondary and the remote node is Primary, and both of them are UpToDate.

For more info check Portal:Data_Services/Admin/Shared_storage#DRBD

Common issues

Add here any issues you might encounter.

Related information

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