Re: [ovirt-users] [Gluster-users] Replicated Glusterfs on top of ZFS

On Mon, Mar 6, 2017 at 3:21 PM, Arman Khalatyan <arm2arm(a)gmail.com&gt; wrote: > > > On Fri, Mar 3, 2017 at 7:00 PM, Darrell Budic <budic(a)onholyground.com&gt; > wrote: > >> Why are you using an arbitrator if all your HW configs are identical? >> I’d use a true replica 3 in this case. >> >> > This was just GIU suggestion when I was creating the cluster it was > asking for the 3 Hosts , I did not knew even that an Arbiter does not keep > the data. > I am not so sure if I can change the type of the glusterfs to triplicated > one in the running system, probably I need to destroy whole cluster. > > > >> Also in my experience with gluster and vm hosting, the ZIL/slog degrades >> write performance unless it’s a truly dedicated disk. But I have 8 spinners >> backing my ZFS volumes, so trying to share a sata disk wasn’t a good zil. >> If yours is dedicated SAS, keep it, if it’s SATA, try testing without it. >> >> > We have also several huge systems running with zfs quite successful over > the years. This was an idea to use zfs + glusterfs for the HA solutions. > > >> You don’t have compression enabled on your zfs volume, and I’d recommend >> enabling relatime on it. Depending on the amount of RAM in these boxes, you >> probably want to limit your zfs arc size to 8G or so (1/4 total ram or >> less). Gluster just works volumes hard during a rebuild, what’s the problem >> you’re seeing? If it’s affecting your VMs, using shading and tuning client >> & server threads can help avoid interruptions to your VMs while repairs are >> running. If you really need to limit it, you can use cgroups to keep it >> from hogging all the CPU, but it takes longer to heal, of course. There are >> a couple older posts and blogs about it, if you go back a while. >> > > Yes I saw that glusterfs is CPU/RAM hugry!!! 99% of all 16 cores used > just for healing 500GB vm disks. It was taking almost infinity compare with > nfs storage (single disk+zfs ssd cache, for sure one get an penalty for > the HA:) ) > Is your gluster volume configured to use sharding feature? Could you provide output of gluster vol info? > > > > _______________________________________________ > Gluster-users mailing list > Gluster-users(a)gluster.org > http://lists.gluster.org/mailman/listinfo/gluster-users >