Was this the client log or the glustershd log? Thanks, Avati On Mon, Jul 9, 2012 at 8:23 AM, Jake Grimmett <jog at mrc-lmb.cam.ac.uk> wrote: > Hi Fernando / Christian, > > Many thanks for getting back to me. > > Slow writes are acceptable; most of our VM's are small web servers with > low traffic. My aim is to have a fully self-contained two server KVM > cluster with live migration, no external storage and the ability to reboot > either node with zero VM downtime. We seem to be "almost there", bar a > hiccup when the self-heal is in progress and some minor grumbles from > sanlock (which might be fixed by the new sanlock in RHEL 6.3) > > Incidentally, the logs shows a "diff" self heal on a node reboot: > > [2012-07-09 16:04:06.743512] I [afr-self-heal-algorithm.c:**122:sh_loop_driver_done] > 0-gluster-rep-replicate-0: diff self-heal on /box1-clone2.img: completed. > (16 blocks of 16974 were different (0.09%)) > > So, does this log show "Granular locking" occurring, or does it just > happen transparently when a file exceeds a certain size? > > many thanks > > Jake > > > > On 07/09/2012 04:01 PM, Fernando Frediani (Qube) wrote: > >> Jake, >> >> I haven?t had a chanced to test with my KVM cluster yet but it should be >> a default things from 3.3. >> >> Just be in mind that running Virtual Machines is NOT a supported things >> for Redhat Storage server according to Redhat Sales people. They said >> towards the end of the year. As you might have observed performance >> specially for write isn?t any near fantastic. >> >> >> Fernando >> >> *From:*gluster-users-bounces@**gluster.org<gluster-users-bounces at gluster.org> >> [mailto:gluster-users-bounces@**gluster.org<gluster-users-bounces at gluster.org>] >> *On Behalf Of *Christian Wittwer >> *Sent:* 09 July 2012 15:51 >> *To:* Jake Grimmett >> *Cc:* gluster-users at gluster.org >> *Subject:* Re: "Granular locking" - does this need to be >> >> enabled in 3.3.0 ? >> >> Hi Jake >> >> I can confirm exact the same behaviour with gluster 3.3.0 on Ubuntu >> 12.04. During the self-heal process the VM gets 100% I/O wait and is >> locked. >> >> After the self-heal the root filesystem was read-only which forced me to >> do a reboot and fsck. >> >> Cheers, >> >> Christian >> >> 2012/7/9 Jake Grimmett <jog at mrc-lmb.cam.ac.uk >> <mailto:jog at mrc-lmb.cam.ac.uk>**> >> >> >> Dear All, >> >> I have a pair of Scientific Linux 6.2 servers, acting as KVM >> virtualisation hosts for ~30 VM's. The VM images are stored in a >> replicated gluster volume shared between the two servers. Live migration >> works fine, and the sanlock prevents me from (stupidly) starting the >> same VM on both machines. Each server has 10GB ethernet and a 10 disk >> RAID5 array. >> >> If I migrate all the VM's to server #1 and shutdown server #2, all works >> perfectly with no interruption. When I restart server #2, the VM's >> freeze while the self-heal process is running - and this healing can >> take a long time. >> >> I'm not sure if "Granular Locking" is on. It's listed as a "technology >> preview" in the Redhat Storage server 2 notes - do I need to do anything >> to enable it? >> >> i.e. set "cluster.data-self-heal-**algorithm" to diff ? >> or edit "cluster.self-heal-window-**size" ? >> >> any tips from other people doing similar much appreciated! >> >> Many thanks, >> >> Jake >> >> jog <---at---> mrc-lmb.cam.ac.uk <http://mrc-lmb.cam.ac.uk> >> ______________________________**_________________ >> Gluster-users mailing list >> Gluster-users at gluster.org <mailto:Gluster-users at gluster.**org<Gluster-users at gluster.org> >> > >> http://gluster.org/cgi-bin/**mailman/listinfo/gluster-users<http://gluster.org/cgi-bin/mailman/listinfo/gluster-users> >> >> > > -- > Dr Jake Grimmett > Head Of Scientific Computing > MRC Laboratory of Molecular Biology > Hills Road, Cambridge, CB2 0QH, UK. > Phone 01223 402219 > Mobile 0776 9886539 > > ______________________________**_________________ > Gluster-users mailing list > Gluster-users at gluster.org > http://gluster.org/cgi-bin/**mailman/listinfo/gluster-users<http://gluster.org/cgi-bin/mailman/listinfo/gluster-users> > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://gluster.org/pipermail/gluster-users/attachments/20120709/908744e2/attachment.htm>
