[DRBD-user] Control syncer speed

[Michael Hierweck]

Hi all,

On 31.03.21 11:32, Michael Hierweck wrote:
> Hi all,
> 
> with DRBD 9.0.25 we experience problem with the syncer rate.
> 
> Using default settings our IO system gets overloaded, especially when multiple resources are be 
> resynced in parallel.
> 
> Neither
> 
> drbdadm peer-device-options --c-plan-ahead=X --c-max-sync-rate=Y <res>
> drbdadm peer-device-options --c-plan-ahead=0 --resync-rate=Y <res>
> 
> seem take any effect even when setting Y to very low values, such as 1M.

we ware able to slow down DRBD sync by applying:

drbdadm peer-device-options --c-plan-ahead=0 --resync-rate=100 <res>

(Yes, 100, not 100M.)

Syslog:

Resync done (total 1212 sec; paused 0 sec; 43256 K/sec)

I cannot explain how this setting fits with the result.

Thanks in advance,

Michael