On 2015-08-13 19:29, Gareth Pye wrote:
> I would have been surprised if any generic file system copes well with
> being mounted in several locations at once, DRBD appears to fight
> really hard to avoid that happening :)
>
> And yeah I'm doing the second thing, I've successfully switched which
> of the servers is active a few times with no ill effect (I would
> expect scrub to give me some significant warnings if one of the disks
> was a couple of months out of date) so I'm presuming that DRBD copes
> reasonably well or I've been very lucky. Either that luck is very
> deterministic, DRBD copes correctly, or I've been very very lucky.
>
> Very very lucky doesn't sound likely.
>
Yeah, I'd be willing to bet that DRBD does cope well with direct writes 
to the backing store (either that or it prevents the kernel from doing 
that, which would be even better and would not surprise me at all).  In 
my experience it's one of the most resilient shared storage options out 
there.