[ovirt-users] gluster performance oVirt 3.4

[Humble Chirammal]

| 
| Citējot Vijay Bellur <vbellur at redhat.com> :
| >  On 05/11/2014 02:04 AM, Vadims Korsaks wrote:
| >  > HI!
| >  >
| >  > Created 2 node setup with oVirt 3.4 and
| CentOS 6.5, for storage created
| >  > 2 node replicated gluster (3.5) fs on same
| hosts with oVirt.
| >  > mount looks like this:
| >  > 127.0.0.1:/gluster01 on
| >  >
| /rhev/data-center/mnt/glusterSD/127.0.0.1:_gluster01
| type fuse.glusterfs
| >  >
| (rw,default_permissions,allow_other,max_read=131072)
| >  >
| >  > when i making gluster test with dd, something
| like
| >  > dd if=/dev/zero bs=1M count=20000
| >  >
| of=/rhev/data-center/mnt/glusterSD/127.0.0.1\:_gluster01/kaka
| >  > i'm gettting speed ~ 110 MB/s, so this is
| 1Gbps speed of ethernet adapter
| >  >
| >  > but with in VM created in oVirt speed is
| lower than 20 MB/s
| >  >
| >  > why there is so huge difference?
| >  > how can improve VMs disks speed?
| >  >
| >
| >  What are your gluster volume settings? Have you
| applied the following
| >  performance tunables in gluster's virt profile:
| >
| >  eager-lock=enable
| >  remote-dio=enable
| >
| >  Regards,
| >  Vijay
| >
| setting were:
| [root at centos155 ~]# gluster volume info gluster01
| 
| Volume Name: gluster01
| Type: Replicate
| Volume ID: 436edaa3-ac8b-421f-aa35-68b5bd7064b6
| Status: Started
| Number of Bricks: 1 x 2 = 2
| Transport-type: tcp
| Bricks:
| Brick1: 10.2.75.152:/mnt/gluster01/brick
| Brick2: 10.2.75.155:/mnt/gluster01/brick
| Options Reconfigured:
| storage.owner-gid: 36
| storage.owner-uid: 36
| 
| 
| add your settings settings now it looks
| 
| [root at centos155 ~]# gluster volume info gluster01
| 
| Volume Name: gluster01
| Type: Replicate
| Volume ID: 436edaa3-ac8b-421f-aa35-68b5bd7064b6
| Status: Started
| Number of Bricks: 1 x 2 = 2
| Transport-type: tcp
| Bricks:
| Brick1: 10.2.75.152:/mnt/gluster01/brick
| Brick2: 10.2.75.155:/mnt/gluster01/brick
| Options Reconfigured:
| network.remote-dio: enable
| cluster.eager-lock: enable
| storage.owner-gid: 36
| storage.owner-uid: 36
| 
| 
| but this didn't affected performace in any big way
| should hosts to be restarted?
| 

glusterfs storage domain configuration GUI got ""Optimize for virt. store" option which have to be enabled when configuring for virt store.

Ref#http://www.ovirt.org/Features/GlusterFS_Storage_Domain

If the configuration is manual,  you need to set the group to 'virt' as shown below

#gluster volume set VOLNAME group virt

This will enable below options on gluster volume :

quick-read=off
read-ahead=off
io-cache=off
stat-prefetch=off
eager-lock=enable
remote-dio=on


Can you please make sure group has set properly ?

Also, invoke  "dd" with oflag=direct option and check whether it helps ..


--Humble