10.11.2011 19:16, Riches Jr, Robert M wrote: > Thank you, Vladislav, for the suggestion. That could potentially > help in cases where the nodes are CPU-bound, likely independent of > whether they are I/O-bound. Except filtering unneeded block devices. This greatly helps in IO-bound setups. > > Thanks, > > Robert Riches > > -----Original Message----- From: linux-lvm-bounces@redhat.com > [mailto:linux-lvm-bounces@redhat.com] On Behalf Of Vladislav > Bogdanov Sent: Thursday, November 10, 2011 1:06 AM To: > linux-lvm@redhat.com Subject: Re: cLVM commands often > taking a long time to execute > > 09.11.2011 03:06, Riches Jr, Robert M wrote: >> I'm running into some odd behavior from clustered LVM commands on a >> 3-node pacemaker-based cluster. When other processes on the nodes >> are doing somewhat heavy sequential I/O traffic, LVM commands such >> as lvs, pvs, vgs, lvdisplay, pvdisplay, and vgdisplay have widely >> variable, often very long execution times. The same LVM command >> done repetitively will have execution times varying from less than >> a second to 10-15 seconds, more rarely up to around 60 seconds. >> Other read-heavy commands such as find, wc, and sum have much less >> variability and much shorter tails in the distribution of their >> execution times. >> >> Is it known what causes the cLVM commands to be so slow at times? >> >> Perchance, are there known ways to get cLVM commands to be less >> slow? > > I use chrt -r 99 for them. And I also run clvmd the same way. But > this is much more about CPU load then IO load. Also, please make sure > that you correctly filter unneeded block devices from being > PV-suspects (filter clause in lvm.conf). > > Best, Vladislav > > _______________________________________________ linux-lvm mailing > list linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO > at http://tldp.org/HOWTO/LVM-HOWTO/ > > _______________________________________________ linux-lvm mailing > list linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO > at http://tldp.org/HOWTO/LVM-HOWTO/ _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
