I thought I might take a minute to update everyone on this situation. I rebuilt the glusterFS using a shard size of 256MB and then imported all VMs back on to the cluster. I rebuilt it from scratch rather than just doing an export/import on the data so I could start everything fresh. I wish now I would have used 512MB but unfortunately I didn’t see that suggestion in time. Anyway, the good news is the system load has greatly decreased. The systems are all now in a usable state.
The bad news is that I am still seeing a bunch of heals and not sure why. Because of that, I am also still seeing the drives slow down from over 110 MB/sec without Gluster running on them to ~ 25 MB/sec with bricks running on the drives. So it seems to me there is still an issue here. Also as fate would have it, I am having issues due to a bug in the Gluster NFS implementation on this version (3.7) that necessitates the need to set nfs.acl to off so also hoping for a fix for that soon. I think this is the bug but not sure: https://bugzilla.redhat.com/show_bug.cgi?id=1238318 So to sum up, things are working but the performance leaves much to be desired due mostly I suspect due to all the heals taking place. - Kyle On Mon, Jan 11, 2016 at 9:32 PM, Pranith Kumar Karampuri < [email protected]> wrote: > > > On 01/12/2016 08:52 AM, Lindsay Mathieson wrote: > >> On 11/01/16 15:37, Krutika Dhananjay wrote: >> >>> Kyle, >>> >>> Based on the testing we have done from our end, we've found that 512MB >>> is a good number that is neither too big nor too small, >>> and provides good performance both on the IO side and with respect to >>> self-heal. >>> >> >> >> Hi Krutika, I experimented a lot with different chunk sizes, didn't find >> all that much difference between 4MB and 1GB >> >> But benchmarks are tricky things - I used Crystal Diskmark inside a VM, >> which is probably not the best assessment. And two of the bricks on my >> replica 3 are very slow, just test drives, not production. So I guess that >> would effevt things :) >> >> These are my current setting - what do you use? >> >> Volume Name: datastore1 >> Type: Replicate >> Volume ID: 1261175d-64e1-48b1-9158-c32802cc09f0 >> Status: Started >> Number of Bricks: 1 x 3 = 3 >> Transport-type: tcp >> Bricks: >> Brick1: vnb.proxmox.softlog:/vmdata/datastore1 >> Brick2: vng.proxmox.softlog:/vmdata/datastore1 >> Brick3: vna.proxmox.softlog:/vmdata/datastore1 >> Options Reconfigured: >> network.remote-dio: enable >> cluster.eager-lock: enable >> performance.io-cache: off >> performance.read-ahead: off >> performance.quick-read: off >> performance.stat-prefetch: off >> performance.strict-write-ordering: on >> performance.write-behind: off >> nfs.enable-ino32: off >> nfs.addr-namelookup: off >> nfs.disable: on >> performance.cache-refresh-timeout: 4 >> performance.io-thread-count: 32 >> cluster.server-quorum-type: server >> cluster.quorum-type: auto >> client.event-threads: 4 >> server.event-threads: 4 >> cluster.self-heal-window-size: 256 >> features.shard-block-size: 512MB >> features.shard: on >> performance.readdir-ahead: off >> >> >> Most of these tests are done by Paul Cuzner (CCed). > > Pranith >
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