Hi there I''m running two servers working as a Xen guest systems - on separate machines. I experience quite similar problems with them. Without any higher CPU usage, load is rising up to the point, when server is unresponsive. CPU usage is low, but I/O wait is very high, so I suspect that that''s the main problem. Both guests are using physical disks. I''ve managed to curb down load on one server by limiting apache instances to the point when no swap is used. On the second one I have 2GB of physical RAM, no swap is being used, but I have terrible problems with MySQL. I keep there quite large database (10GB) - dump of Wikipedia. Any maintenance jobs (index regeneration etc) on this db lead to very high load and eventually server crash. I''ve written a script to cope with this (do 10 jobs, check load, if load is reasonable go on, else - wait until load is ok), but still web access is very slow. Any hints on what to do now? Xens are hosted by my friend who has no problems with other guests. Regards Leszek
Leszek Krupiński wrote:> Hi there > > I'm running two servers working as a Xen guest systems - on separate > machines. I experience quite similar problems with them. Without any > higher CPU usage, load is rising up to the point, when server is > unresponsive. CPU usage is low, but I/O wait is very high, so I suspect > that that's the main problem.(cut) Some additional info. Under load, I get some filesystem errors. FS remounts automatically to read-only mode, and only thing I can do with it is to reboot guest system. Leszek _______________________________________________ xen-discuss mailing list xen-discuss@opensolaris.org
Hi Leszek, Leszek Krupiński wrote:> Leszek Krupiński wrote: >> Hi there >> >> I'm running two servers working as a Xen guest systems - on separate >> machines. I experience quite similar problems with them. Without any >> higher CPU usage, load is rising up to the point, when server is >> unresponsive. CPU usage is low, but I/O wait is very high, so I suspect >> that that's the main problem. > > (cut) > > Some additional info. Under load, I get some filesystem errors. FS > remounts automatically to read-only mode, and only thing I can do with > it is to reboot guest system.Need some more info... What OS & OS version is the dom0. What version of Xen does it have? What devices do you have in dom0? What OS & OS version/build are the guest OSes? Thanks, MRJ _______________________________________________ xen-discuss mailing list xen-discuss@opensolaris.org