[linux-lvm] Reliability

[Michael Marxmeier]

> Quorum support is a solution to deal with the activation of a VG without having
> all PVs available which belong to it.
> 
> This actually is usefull in case you have associated all LEs of specific LVs
> to available PVs and want to access those.
> In real life scenarios this can't be garanteed though which leads to partitally
> destroyed (unusable) LV contents and in consequence to filesystem errors.
> 
> Therefore qourum is IMO not really usefull.
> 
> The tradeoff of the existing solution nevertheless is that reconstruction of
> the partition table and the VGDA is necessary on a replacement disk (subsystem)
> which takes some time :-{(
> After this we almost have the same scenario as with quorum.
> The difference is that no I/O errors are returned in case of accessing
> bad LEs.

As far as i can see Quorum support looks like the saner option:
If you loose a disk and only restore the partition table and VGDA
the replacement disk still mostly contains garbage (eg. not a fs).
So we could as well activate the VG and leave LVs with extents
on offline PVs disabled?

Any reason why this might not work?

Michael

--
Michael Marxmeier           Marxmeier Software AG
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