[DRBD-user] sync rate only 2,204 (1,220) K/sec?

Peter Sabaini peter at sabaini.at
Wed Oct 4 16:22:00 CEST 2006

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


On Wednesday 04 October 2006 16:19, Milind Dumbare wrote:
> On Wed, 2006-10-04 at 16:09 +0200, Peter Sabaini wrote:
> > Hello list,
> >
> > I experimented with drbd a bit; on my first sync it says this in
> > /proc/drbd:
> >
> > # cat /proc/drbd
> > version: 0.7.20 (api:79/proto:74)
> > SVN Revision: 2260 build by debuild at build64-dapper, 2006-07-20 16:42:44
> >  0: cs:SyncSource st:Secondary/Secondary ld:Consistent
> >     ns:3214256 nr:0 dw:0 dr:3219148 al:0 bm:196 lo:0 pe:182 ua:1223 ap:0
> >         [=>..................] sync'ed:  5.7% (52205/55344)M
> >         finish: 6:11:14 speed: 2,204 (1,220) K/sec
> >
> > This seems extremely slow -- Hardware is 2xHP DL385 on a Procurve Switch
> > with Gigabit connection between them.
> >
> > The syncer rate in drbd.conf is set to 50M, Protocoll is "C"
> >
> > dstat gives me:
> >
> > # dstat 1
> > ----total-cpu-usage---- -disk/total -net/total- ---paging-- ---system--
> > usr sys idl wai hiq siq|_read write|_recv _send|__in_ _out_|_int_ _csw_
> >   0   1   8  90   0   0|   0     0 |   0     0 |   0     0 |1109  1449
> >   0   0   0 100   0   0|   0     0 |2880k  161k|   0     0 |1249  1554
> >   0   1   0  98   0   1|   0     0 |2990k  135k|   0     0 |1144  1410
> >   0   0   0 100   0   0|   0     0 |3004k  152k|   0     0 |1177  1343
> >   0   0   0 100   0   0|   0     0 |2893k  148k|   0     0 |1161  1391
> >   0   0   0 100   0   0|   0     0 |2852k  150k|   0     0 |1197  1451
> >   0   0   0  99   0   0|   0     0 |5915k  306k|   0     0 |2400  2842
> >
> >
> > Usually, I can push 110MB/sec over the wire via NFS.
> >
> > Am I missing something? Is it only the initial sync thats slow?
>
> Do you have fast i/o backend? See "$hdparm -t <underlying io device>.

# hdparm -t /dev/cciss/c0d0

/dev/cciss/c0d0:
 Timing buffered disk reads:  208 MB in  3.03 seconds =  68.69 MB/sec

It could be better, but its reasonable I think?

 - peter.

> > Thanks for any pointers!
> > peter.
> >
> >
> >
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> > drbd-user at lists.linbit.com
> > http://lists.linbit.com/mailman/listinfo/drbd-user



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