"Ulrich Windl" <ulrich.wi...@rz.uni-regensburg.de> writes: >>>> Ferenc Wágner <wf...@niif.hu> schrieb am 28.08.2017 um 18:07 in Nachricht > <87mv6jk75r....@lant.ki.iif.hu>: > > cLVM under I/O load can be really slow (I'm talking about delays in the range > of a few seconds).
Yes, I know, and it's really annoying. I wonder why this needs to be so... There really should be a way to tune that, but I never digged into the issue, just switched off the VG activation timeout instead. > Be sure to have any timeouts adjusted accordingly. I wrote a tool that > allows to monitor the read latency (as seen by applications), so I > know these numbers. Do you mean the LVM metadata read latency as seen by the LVM tools or that of a mirrored data region? > And things get significantly worse if you do cLVM mirroring with a > mirrorlog replicated to each device. I don't do any such things, so my data paths are independent of cLVM and DLM. And in this thread I'm trying to stress that my issue should be independent of any disk related latency, because everything is in memory already. > Maybe the CLVM slows down at n^2, where n is the number of nodes; I > don't know ;-) It's a pig for sure. -- Thanks, Feri _______________________________________________ Users mailing list: Users@clusterlabs.org http://lists.clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
