[DRBD-user] Consistent before first-time sync? Unknown error 990?

Lars Ellenberg Lars.Ellenberg at linbit.com
Thu Jun 23 10:08:23 CEST 2005

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

/ 2005-06-23 14:55:07 +0800
\ David Huang:
> Hello Everyone
> I set up two machines and running DRBD(0.7.11) on top of LVM2 with
> kernel 2.6, I use XFS filesystem. Everything works fine most of time,
> however sometimes when I create a new drbd device(lvsize to extend
> volumes by 128MB, setup configure file then drbdadm up all & drbdadm
> secondary all), as soon as I make two sides to Secondary, "cat
> /proc/drbd" shows the device is Consistent before I set one side to
> Primary. Isn't it suppose to be "InConsistent" before first-time
> synchronize?

if you played around quite a bit, chances are that you lvremoved a
"valid" meta data thing, then lvcreated an other again at the same
physical place using the same (stale) physical data...

and that (stale) meta data block is likely to contain wrong data now
(size, consistent flag, generation counters, bitmap).

to avoid that,
  lvcreate -n new-drbd#-md -L 128M ...
  dd if=/dev/zero of=/dev/.../new-drbd#-md bs=1M count=1
  drbdsetup /dev/drbd# disk /dev/storage /dev/.../new-drbd#-md 0 ...

or you did have one peer set up already, which was "consistent", but,
because you played that much, contains unrelated data, and now you create
a "new" device on the other peer, that connects itself to the other,
syncs up, and whoops, sync is done, device consistent...

just have a look into syslog.

> it's an issue to me because when it happened, if I make one side to
> primary and try to mount the device, I am unable to mount
> occasionially, the console shows "mount: Unknown error 990"

sorry for asking, but
you are sure you did mkfs before that?

or, scenario "peer consistent but unrelated data", you just synced some
unrelated data blocks into your filesystem and corrupted it.

: Lars Ellenberg                                  Tel +43-1-8178292-0  :
: LINBIT Information Technologies GmbH            Fax +43-1-8178292-82 :
: Schoenbrunner Str. 244, A-1120 Vienna/Europe   http://www.linbit.com :
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