[DRBD-user] online verification really bogs things down

Florian Haas florian.haas at linbit.com
Sun Jul 20 08:39:51 CEST 2008

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

Gregor Mosheh wrote:
> Online verification - very neat. Combined with the realtime write
> verification, this should completely eliminate the possibility of the
> data ever not being identical.
> However, running an online verification is really intensive, as was
> warned in the manual. So intensive is it, that the rest of the system
> comes near to useless.

Let me guess... your syncer rate is way above what your storage
subsystem and/or network can handle?

> Does there exist a way to renice it or ionice it to reduce the load it
> causes, or to pause it? For example, what drbd.conf directives would be
> relevant to the verification speed as opposed to the sync speed?

No. The syncer rate also throttles online verification. So, the
considerations outlined in
http://www.drbd.org/users-guide/s-configure-syncer-rate.html also apply
to online verify. If you don't follow the rules of thumb outlined there,
both online verify and background sync are likely to bog down your system.


: Florian G. Haas
: LINBIT Information Technologies GmbH
: Vivenotgasse 48, A-1120 Vienna, Austria

When replying, there is no need to CC my personal address.
I monitor the list on a daily basis. Thank you.

More information about the drbd-user mailing list