[DRBD-user] corrupted resource can't be fixed be rolling back to old snapshot

[Michael Labriola]

On Tue, Aug 2, 2022 at 6:44 AM Chitvan Chhabra <chitvan1988 at gmail.com> wrote:
>
> Though i could be wrong here , but what  i understand is:
>
> After Roll back Scenerio:
>
> A( Primary Snapshot rollbacked to  time: say 12:10:00 PM)  , B(Secondary Snapshot  roll backed to time say 12:09:00 PM)

Yes.

>
> Current time say : 12:30:00 PM
> Now A must have received acks(in the past of ofcource) from B between 12:09:00 to 12:10:00 PM , now at 12:09:01 B says i dont have the data which might have confused A as it must be saying saying that you have already acked me few data , then how can you say now that i don't have the data now.Hence the Error.This is just my thought.Or does DRBD support such scenario, if yes then that is awesome than as that prevent complete resynchronization of data.

Normally, yes this works and it's just as awesome as it sounds.  But
in this particular case, it's utterly broken.  With the resource down
on both nodes, trying to raise it on either basically wigs out and
says "what is this block device?"  Any calls to drbdadm, drbdmeta,
etc, result in a couple dozen "extent beyond end of bitmap" error
messages.  Rolling back to an older snapshot results in the exact same
error messages, which was quite unexpected.

>
> Anyways with DRBD Down , you can always get the data back from ZVOL snapshot(otr its clone) itself(assuming DRBD metadata doesnot contain actual data  ?? )

Yes, I was able to create a new DRBD resource and copy my data into
it... but the initial sync for this resource takes 3-4 days... and I
don't want to have to do that all the time.

>
>
>
>
> On Tue, 2 Aug 2022 at 15:04, Roland Kammerer <roland.kammerer at linbit.com> wrote:
>>
>> On Tue, Aug 02, 2022 at 02:54:02PM +0530, Chitvan Chhabra wrote:
>> > Unable to see the older thread.May Be it is just me.Request to share older
>> > conversation as well please.
>>
>> we have an archive:
>> https://lists.linbit.com/pipermail/drbd-user/2022-July/026252.html
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--
Michael D Labriola
401-316-9844 (cell)