[DRBD-user] BAD! BarrierAck

Nathan Stratton nathan at robotics.net
Fri Dec 12 16:04:44 CET 2008

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


On Fri, 12 Dec 2008, Lars Ellenberg wrote:

> On Thu, Dec 11, 2008 at 08:14:17PM -0600, Nathan Stratton wrote:
>> On Thu, 11 Dec 2008, Nathan Stratton wrote:
>>
>>> Anyidea how to fix this? I keep getting them when trying to sync two
>>> large systems.
>>
>> Running drbd-8.3.0rc2 on Centos 5.2
>>
>>> Dec 11 19:59:44 xen1 kernel: drbd0: BAD! BarrierAck #3231051334
>>> received, expected #3231051333!
>
> verry interessting.
> this is new paranoia code,
> leading to reconnection.
> no harm done.

yep, only issue is access to local /dev/drbd0 frezes runing the 
disconnect/reconnect of the remote notes.

> but,
> can you give some more details?

For you? Sure!

> how long between two such "BAD!"s, wall clock time and approx. amount of
> written data?

Looks random, can be 100G or 2G, wall clock looks like:

Dec 11 14:11:02 xen1 kernel: drbd0: BAD! BarrierAck #2399440554 received, expected #2399440553!
Dec 11 15:06:08 xen1 kernel: drbd0: BAD! BarrierAck #3562915500 received, expected #3562915499!
Dec 11 15:10:16 xen1 kernel: drbd0: BAD! BarrierAck #2877127253 received, expected #2877127252!
Dec 11 17:12:49 xen1 kernel: drbd0: BAD! BarrierAck #684515493 received, expected #684515492!
Dec 11 18:07:11 xen1 kernel: drbd0: BAD! BarrierAck #1304938437 received, expected #1304938436!
Dec 11 18:40:48 xen1 kernel: drbd0: BAD! BarrierAck #2899175375 received, expected #2899175374!
Dec 11 18:55:46 xen1 kernel: drbd0: BAD! BarrierAck #229959413 received, expected #229959412!
Dec 11 19:59:44 xen1 kernel: drbd0: BAD! BarrierAck #3231051334 received, expected #3231051333!
Dec 11 20:00:17 xen1 kernel: drbd0: BAD! BarrierAck #1512535064 received, expected #1512535063!


> what access pattern?

All access right now is on the Primary/UpToDate system.

> only sync?

Unknown since I am not doing much else.

> what is "large"?

/dev/drbd0            9.6T  218G  9.4T   3% /share

> what is your hardware/io subsys/network/drivers?

3Ware 9650SX with 16 760 gig disks, network is Mellanox MT25204 10 Gb/s 
with IPoIB since direct infiniband is not yet supported. : )

> can you give me a "dmesg | grep drbd"
> from module load to first mount of file system?

http://share.robotics.net/drbd0


><>
Nathan Stratton                                CTO, BlinkMind, Inc.
nathan at robotics.net                         nathan at blinkmind.com
http://www.robotics.net                        http://www.blinkmind.com



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