xlog_write: reservation ran out. Need to up reservation

[Thomas Klaube]

----- Ursprüngliche Mail -----
> Von: "Dave Chinner" <david at fromorbit.com>
> An: "Thomas Klaube" <thomas at klaube.net>
> CC: xfs at oss.sgi.com
> Gesendet: Mittwoch, 20. August 2014 00:55:07
> Betreff: Re: xlog_write: reservation ran out. Need to up reservation

Hi,

> Can you post the fio job configuration?

first I run this job for 600 sec:
wtk at ubuntu ~ $ cat write.fio
[rnd]
rw=randwrite
ramp_time=30
runtime=600
time_based
gtod_reduce=1
size=100g
refill_buffers=1
directory=.
iodepth=64
direct=1
blocksize=16k
numjobs=64
nrfiles=1
group_reporting
ioengine=libaio
loops=1

Then I run this job for 2hours:
wtk at ubuntu ~ $ cat random.fio
[rnd]
rw=randrw
ramp_time=30
runtime=7200
time_based
rwmixread=30
size=100g
refill_buffers=1
directory=.
iodepth=64
direct=1
blocksize=4k
numjobs=64
group_reporting
ioengine=libaio
loops=1

I run this workload on 2 devices in parallel. One is the bcache device (with xfs), the other is
a non cached device. The random.fio job causes the problem on the bcache device after ~30-75mins.

> http://xfs.org/index.php/XFS_FAQ#Q:_What_information_should_I_include_when_reporting_a_problem.3F

I have sent a mail with all collected data to Dave.

> Run the workload directly on the SSD rather than with bcache. Use
> mkfs parameters to give you 8 ags and the same size log, and see
> if you get the same problem.

I created a xfs direclty on the SSD:
mkfs.xfs -f -d agcount=8 -l size=521728b /dev/sdc1

Then I started tho fio jobs as described above for 10 hours. I could not reproduce the
problem. I will send a mail to the bcache mailing list as well...

Thanx and Regards
Thomas