[DRBD-user] Performance issues / noticable DRBD overhead

Lars Marowsky-Bree lmb at suse.de
Fri Jul 17 11:09:54 CEST 2009

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


On 2009-07-16T18:04:24, Lars Ellenberg <lars.ellenberg at linbit.com> wrote:

> > A. on drbd-volume as it is. Replication in protocol C activated
> > B. on drbd-volume, replication stopped (other node shut down)
> > C. on physical ext3 partition, to test the subsystems performance
> 
> are you comparing OCFS2 vs ext3 results here?


> > File Write 1024 bufsize, 2000 blocks
> > ------------------------------------
> >    1 thread      4 threads
> > A:  16,48 MB/s    11,62 MB/s
> > B:  17,65 MB/s    12,70 MB/s
> > C:  46,19 MB/s    28,08 MB/s
> 
> and about 5 to 10 % overhead on writes,
> (unless you have a bottleneck).

This also smells like internal meta-data, which will incur quite a bit
of additional seeks if it's all on one disk, and have a rather high
impact on performance.



Regards,
    Lars

-- 
Architect Storage/HA, OPS Engineering, Novell, Inc.
SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nürnberg)
"Experience is the name everyone gives to their mistakes." -- Oscar Wilde




More information about the drbd-user mailing list