[DRBD-user] "kernel: bio too big device drbd0"

Lutz Vieweg lvml at 5t9.de
Tue Jun 4 11:56:34 CEST 2013

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


Hi,

I recently increased the size of a DRBD, first increasing the
underlying Logical Volume with a command like
  lvresize --nofsck --extents N DataVG/DataLV
then I invoked
  drbdadm resize ResourceData
and finally
  cryptsetup resize cryptedResourceData
to also increase the size of a LUKS device that exists
on top of the drbd0 device.

The procedure so far worked fine, I should also mention that
the same procedure worked fine some years ago for a preceding
capacity increase.

The filesystem that resides on the LUKS device has not yet
been increased in size, because of this bug:
  https://bugzilla.redhat.com/show_bug.cgi?id=909602
so the filesystem resize will need to wait for a kernel
update (planned soon).
Last time we added capacity, the xfs_grow went fine.

What concerns me is that after the resizing, /var/log/messages
accumulated a few dozen of these messages (only on the primary):
> Jun  4 10:56:40  kernel: bio too big device drbd0 (304 > 256)
> Jun  4 10:56:40  kernel: bio too big device drbd0 (264 > 256)
> Jun  4 10:56:40  kernel: bio too big device drbd0 (384 > 256)
> Jun  4 10:56:42  kernel: bio too big device drbd0 (512 > 256)
> Jun  4 10:57:05  kernel: bio too big device drbd0 (512 > 256)
> Jun  4 11:12:07  kernel: bio too big device drbd0 (376 > 256)

The system does not yet show any abnormal behaviour, it has
been running busy for some days after the first of those messages
appeared.
Should I be worried?

(A "verify" is currently running at 80%, no differences have been found
  to the secondary so far.)

[This is not directly related to my recent question about compiling
  drbd-8.4.3 for linux-3.9.4, the observation is from a different
  server that is currently running linux 3.7.6 with drbd-8.4]

Regards,

Lutz Vieweg





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