[DRBD-user] Incorrect syncer rate

Digimer linux at alteeve.com
Mon Aug 22 17:14:14 CEST 2011

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

On 08/22/2011 11:11 AM, Lyre wrote:
> Hi all:
>   After manual manually recovery from split-brain, I noticed the syncer
> rate was limited to  250kb/s (cat /proc/drbd) , which was default value
> of drbd . However, It was configured to 10M, drbdadm can confirm this. 
> After running drbdadm adjust drbd0, the syncer rate was correct. What's
> the problem with it?
> I'm using drbd0 8.3.11 on SLES 11 SP1 x86_64, kernel, and
> I compiled the rpm packages myself.

There is no problem. The default sync rate is set to be low so that
background sync doesn't interfere with "real" traffic.

If you want to change the default, look at 'syncer' in the drbd.conf man
page. Keep in mind, setting a sync rate too high will hurt performance
and can stall the sync all together. It is advised that you run
benchmarks (ie: bonnie++) to find out what the maximum *practical* disk
I/O is and then set 'syncer' to no more than 30% of that speed.

E-Mail:              digimer at alteeve.com
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