philipp.reisner at linbit.com
Fri Oct 19 13:53:49 CEST 2012
Besides bug-fixes this release brings support for FLUSH/FUA for the
layers that get stacked on top of DRBD.
Talking of bugs of previous releases: It needs to be pointed out
that as the barrier-support was removed in upstream kernel (2.6.36),
it was no longer save to run DRBD in protocol A or B with barriers
In case you...
* use protocol A or B
* have a kernel >= 2.6.36 (or 2.6.32 if it is RHEL6/CentOS6 or other clone)
* have DRBD <= 8.3.13
* do not have the option "no-disk-barrier" set. (= barriers enabled)
you might get write reordering on secondary, which is bad.
Your possible ways out:
* Add "no-disk-barrier" to your config
* Upgrade to drbd-8.3.14
Note: You are only affected if all of the 4 conditions are true.
You solved the issue if you take _one_ of the two described ways out.
* No longer support write-ordering "barrier" on kernels newer than 2.6.36
(or RHEL's 2.6.32), since it is no longer supported by the kernel's IO-layer
* Fixed the cause of the "ASSERT FAILED tl_hash..." messages
* Fixed an OOPS in case a on-congestion policy was set and the node becomes
* Fixed a list corruption for read requests that complete with an error
after they were aborted
* Fixed a kernel panic if the device size was an exact multiple of 128MiB
* Finish requests that completed while IO on DRBD was frozen. Before such
requests where never completed by DRBD
* Fixed a potential memory allocation during deadlock online resize
* Online resize with internal meta data failed to write the bitmap to
the new on-disk-location after the resize operation. This issue was
introduced with 8.3.10
* Do not go through NetworkFailure state during a regular disconnect
* Improve the handling of read-errors: Make sure that sectors that had a
read error are overwritten with data from the peer on the next resync
* Expose the data-generation-uuids through /sys/block/drbdXX/drbd/
* Add a stop-sector to the online verify feature
* Support FLUSH/FUA for layers above DRBD
* The new flag --peer-max-bio-size for drbdmeta create-md is of use
if you plan to use the device for long time without peer
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