Hi Folks, I am aware that I can throttle a DomU''s disk usage by using ionice in the Dom0 against the correct blkback process. However, how does one actually find out what the "offending" DomU is? Thanks _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi,> I am aware that I can throttle a DomU''s disk usage by using ionice in the > Dom0 against the correct blkback process. However, how does one actually > find out what the "offending" DomU is?if it''s enough to find out "after" the fact - meaning, when there already IS excessive disk IO, then iotop is the very best thing since sliced bread. imho even better than top :) Can you also give https://bitbucket.org/darkfader/black-magic/src/d14a84157990/usr/local/bin/blksched a test run in this situation and let me know if it helps for you? Florian -- the purpose of libvirt is to provide an abstraction layer hiding all xen features added since 2006 until they were finally understood and copied by the kvm devs. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On 16/06/2011 22:14, Florian Heigl wrote:> Hi, > >> I am aware that I can throttle a DomU''s disk usage by using ionice in the >> Dom0 against the correct blkback process. However, how does one actually >> find out what the "offending" DomU is? > if it''s enough to find out "after" the fact - meaning, when there > already IS excessive disk IO, then iotop is the very best thing since > sliced bread. > imho even better than top :) > > Can you also give > https://bitbucket.org/darkfader/black-magic/src/d14a84157990/usr/local/bin/blksched > a test run in this situation and let me know if it helps for you? > > Florian > >Hi Florian, Thanks for the tips. I discovered ionice and tried to use it. It did help, however maybe for only a few minutes. However, could this be because I''m only setting the ionice parameters for the "offending" VPS? Also, I was thinking of writing a script that could find the process ID of the blkback process so could script this to run after DomU startup. Am I only the right lines here? Thanks _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi, 2011/6/16 Jonathan Tripathy <jonnyt@abpni.co.uk>:>> https://bitbucket.org/darkfader/black-magic/src/d14a84157990/usr/local/bin/blksched >> a test run in this situation and let me know if it helps for you?> Thanks for the tips. I discovered ionice and tried to use it. It did help, > however maybe for only a few minutes. However, could this be because I''m > only setting the ionice parameters for the "offending" VPS?That sounds very strange, but normally I''ve been lucky and only had medium-low load.> Also, I was thinking of writing a script that could find the process ID of > the blkback process so could script this to run after DomU startup. Am I > only the right lines here?look in my script, it does that - at least as far as I remember. Going to bed now ;) But really, the point with the script was to blindly launch it if some condition (i.e. high disk avg service time) is met. It should get all active disk / blkdev processes. There''s a second script called cpusched that does the same clamping for running domUs AND raises the "weight" of dom0. I have done a little testing and while they are not perfect they seem really be able to throttle any excessive VMs. Flo -- the purpose of libvirt is to provide an abstraction layer hiding all xen features added since 2006 until they were finally understood and copied by the kvm devs. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users