[DRBD-user] Problem mounting lvm snapshot

Lewis Donzis lew at pt.net
Wed Oct 27 14:56:33 CEST 2010

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.


> I take this as a sign that you have damaged your fs with that 
> create-md.
> You should not use this disk in production as is.

I was worried as well, but found the same symptoms when doing it several
ways which should have been safe:
1. mkfs on backing device, then shrink fs by amount requested by
create-md, then create-md
2. mkfs on backing device, then lvresize +128m, then create-md
3. create-md/attach, then mkfs on drbd device, shut down drbd and attempt
to mount backing device.

All of these should theoretically be ok, and fsck -f in all cases says
that the filesystem is ok.

> I'm not at all familiar with ext4, but this does seem very 
> strange, especially seeing as it can be mounted when giving 
> the specific type.

I agree, that's what caused the confusion in the first place.  I'll
re-test with ext3 and see if there's any difference.

It's also interesting that mount's autodetection specifically claimed this
as a "drbd" filesystem, even though there's obviously no such thing.

lew



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