[DRBD-user] Proxmox:Linstore, new third node, all volumes diskless, why?

[Gábor Hernádi]

Hi,

> But all the volumes are now and remain in diskless state on Hydra1?

when you added the third node, the command `node create Hydra1` triggered
Linstor's auto-tiebreaker feature. DRBD can use quorum[1] (useful if your
cluster gets split), but needs 3 peers for that (so there can be a majority
of still connected nodes, which is kinda difficult with only 2 peers). That
is the reason why Linstor automatically deploys all resources where you
already had 2 diskful replicas to the third as diskless peer. You can also
check the .res files to see that quorum is now active on all your
DRBD-resources.

A Linstor-managed tiebreaking resource is by default hidden/filtered in the
`resource list`. You can still show them with `resource list --all`.

> But in the end the DRBD-Device is still diskless on Hydra1

That will also stay this way until you tell Linstor to do something
differently.

> How do I get the volumes also DRBD-replicated onto the third node?

Usually Linstor complains if you try to create a resource while the
resource is already deployed on the given node ("resource already exists"
or something like that).
However, Linstor's tiebreaker is different as that one allows you to either
`resource create Hydra1 $resource -s ...` or do a `resource toggle-disk
Hydra1 $resource -s ...`, whereas for the special case of Linstor
tiebreakers, the first method will internally be mapped to the second one :)

For me everything looks normal / as expected.

Best regards,
Gabor


[1]
https://www.linbit.com/drbd-user-guide/drbd-guide-9_0-en/#s-feature-quorum
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