With some recent posts regarding Arbiter, I’m a little confused… I understand Replica 2 you can’t get a quorum to prevent split brains, but does that only apply to having 2 servers?
If I have 4 servers running distribute 2 replica 2, I still get quorum right? I don’t need to add an arbiter volume, or do I ? What if I have 4 servers running distribute 2 replica 2 and I have 2 additional servers that are part of the pool, but not running bricks, do I still need replica 3 arbiter 1 for HA? > On Mar 22, 2016, at 8:48 AM, André Bauer <aba...@magix.net> wrote: > > Hi Russel, > > i'm a KVM user but imho XEN also supports accessing vm images through > libgfapi so you don't need to mount via NFS or fuse client. > > Infos: > http://www.gluster.org/community/documentation/index.php/Libgfapi_with_qemu_libvirt > > <http://www.gluster.org/community/documentation/index.php/Libgfapi_with_qemu_libvirt> > > Second point is that you need to have at least 3 replicas to get a > working HA setup, because server quorum does not work for 2 replicas. > > Infos: > https://www.gluster.org/pipermail/gluster-users/2015-November/024189.html > <https://www.gluster.org/pipermail/gluster-users/2015-November/024189.html> > > Regards > André > > > Am 20.03.2016 um 19:41 schrieb Russell Purinton: >> Hi all, Once again I’m trying to get XenServer working reliably with >> GlusterFS storage for the VHDs. I’m mainly interested in the ability to >> have a pair of storage servers, where if one goes down, the VMs can keep >> running uninterrupted on the other server. So, we’ll be using the >> replicate translator to make sure all the data resides on both servers. >> >> So initially, I tried using the Gluster NFS server. XenServer supports >> NFS out of the box, so this seemed like a good way to go without having >> to hack XenServer much. I found some major performance issues with this >> however. >> >> I’m using a server with 12 SAS drives on a single RAID card, with dual >> 10GbE NICs. Without Gluster, using the normal Kernel NFS server, I can >> read and write to this server at over 400MB/sec. VMS run well. However >> when I switch to Gluster for the NFS server, my write performance drops >> to 20MB/sec. Read performance remains high. I found out this is due to >> XenServer’s use of O_DIRECT for VHD access. It helped a lot when the >> server had DDR cache on the RAID card, but for servers without that the >> performance was unusable. >> >> So I installed the gluster-client in XenServer itself, and mounted the >> volume in dom0. I then created a SR of type “file”. Success, sort of! I >> can do just about everything on that SR, VMs run nicely, and performance >> is acceptable at 270MB/sec, BUT…. I have a problem when I transfer an >> existing VM to it. The transfer gets only so far along then data stops >> moving. XenServer still says it’s copying, but no data is being sent. I >> have to force restart the XenHost to clear the issue (and the VM isn’t >> moved). Other file access to the FUSE mount still works, and other VMs >> are unaffected. >> >> I think the problem may possibly involve file locks or perhaps a >> performance translator. I’ve tried disabling as many performance >> translators as I can, but no luck. >> >> I didn’t find anything interesting in the logs, and no crash dumps. I >> tried to do a volume statedump to see the list of locks, but it seemed >> to only output some cpu stats in /tmp. >> >> Is there a generally accepted list of volume options to use with Gluster >> for volumes meant to store VHDs? Has anyone else had a similar >> experience with VHD access locking up? >> >> Russell >> >> >> _______________________________________________ >> Gluster-users mailing list >> Gluster-users@gluster.org <mailto:Gluster-users@gluster.org> >> http://www.gluster.org/mailman/listinfo/gluster-users >> <http://www.gluster.org/mailman/listinfo/gluster-users> >> > > > -- > Mit freundlichen Grüßen > André Bauer > > MAGIX Software GmbH > André Bauer > Administrator > August-Bebel-Straße 48 > 01219 Dresden > GERMANY > > tel.: 0351 41884875 > e-mail: aba...@magix.net <mailto:aba...@magix.net> > aba...@magix.net <mailto:aba...@magix.net> <mailto:Email> > www.magix.com <http://www.magix.com/> <http://www.magix.com/ > <http://www.magix.com/>> > > Geschäftsführer | Managing Directors: Dr. Arnd Schröder, Klaus Schmidt > Amtsgericht | Commercial Register: Berlin Charlottenburg, HRB 127205 > > Find us on: > > <http://www.facebook.com/MAGIX <http://www.facebook.com/MAGIX>> > <http://www.twitter.com/magix_de <http://www.twitter.com/magix_de>> > <http://www.youtube.com/wwwmagixcom <http://www.youtube.com/wwwmagixcom>> > <http://www.magixmagazin.de <http://www.magixmagazin.de/>> > ---------------------------------------------------------------------- > The information in this email is intended only for the addressee named > above. 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