On Fri, Apr 01, 2005 at 04:25:41PM -0500, Gregory (Grisha) Trubetskoy wrote: > > > I would also keep measurements of CPU ticks used. Since IO requires CPU > cycles - is it possible that a CPU sched_hard indirectly limits IO just as > well?
my suggestion (and actually plans for I/O issues) are something like this: - have a 'generic' token bucket for various things (swap pages, I/O, scheduler, forks ...) why?: because! no seriously if we put all into one bucket it might work, but nobody can figure why it works/doesn't work ... - make those token buckets per cpu with (the now possible) cpuaffinity in place for vservers why?: increased performance and better scaling - have some buckets affect the scheduling behaviour (e.g. swap, forks, scheduler of course) why?: to penalize the contexts which do heavy forking or other heavy system activity ... - use some buckets to adjust/influence schedulers (taks, I/O and maybe network scheduler that is) sched_hard does already indirectly limit I/O, because a not running process/context can not submit I/O requests so that is already working, but I take it isn't sufficient for 'normal' use ... best, Herbert PS: keep up the discussion ... > Grisha > > On Fri, 1 Apr 2005, Matthew Nuzum wrote: > > >>On Thu, Mar 31, 2005 at 09:22:10PM -0600, Matthew Nuzum wrote: > >>>I think I can create a test case for this. I have a server that is not > >>>currently running any vserver stuff that will be ok with a reboot now > >>and > >>>then. > >> > >>sounds good, please try to get 1.9.5.5 working there, > >>because it already contains some blkio accounting > >>and it would be very interesting to monitor those > >>values ... (maybe with rrdtools) > >> > >>TIA, > >>Herbert > > > >I'm still doing my month-end backup, but when that's done I'll start > >installing the vserver 1.9.5.5. > > > >Here is the test case that seems most logical to me, but advice on how to > >actually do concrete tests would be useful. > > > >1. Create two vservers (vsa and vsb), start both. > >2. In vsa start some heavily i/o intensive operation > >3. In vsb try to do some tasks and notice how much i/o bandwidth I have > >available. > > > >Alternative plan: > >1. Create 1 vserver and start it > >2. In the vserver, start some heavily i/o intensive operation > >3. In the host server try to do some tasks and notice how much i/o > >bandwidth > >I have available > >4. After step 2 completes, in host server start a heavily i/o intensive > >operation > >5. In vserver, try to do some tasks and notice how much i/o bandwidth I > >have > >available > > > >I have two ideas on heavily i/o intensive operation > >1. I have a database with 35 million records. Doing any aggregate function > >such as max() requires several sequential scans and takes a significant > >amount of time. > >2. Preparing my month end backup requires copying 13 GB of data. > > > >Any other suggestions? > > > >Question: > >I have only subjectively noticed a dramatic decrease in server performance > >when a vserver is performing i/o intensive tasks. How can I objectively > >measure and produce concrete numbers? > > > >-- > >Matthew Nuzum <[EMAIL PROTECTED]> > >www.followers.net - Makers of "Elite Content Management System" > >View samples of Elite CMS in action by visiting > >http://www.followers.net/portfolio/ > > > >_______________________________________________ > >Vserver mailing list > >Vserver@list.linux-vserver.org > >http://list.linux-vserver.org/mailman/listinfo/vserver > > > _______________________________________________ > Vserver mailing list > Vserver@list.linux-vserver.org > http://list.linux-vserver.org/mailman/listinfo/vserver _______________________________________________ Vserver mailing list Vserver@list.linux-vserver.org http://list.linux-vserver.org/mailman/listinfo/vserver