[ovirt-users] storage issue's with oVirt 3.5.1 + Nexenta NFS

[Maikel vd Mosselaar]

Hi,

We are running ovirt 3.5.1 with 3 nodes and seperate engine.

All on CentOS 6.6:
3 x nodes
1 x engine

1 x storage nexenta with NFS

For multiple weeks we are experiencing issues of our nodes that cannot 
access the storage at random moments (atleast thats what the nodes think).

When the nodes are complaining about a unavailable storage then the load 
rises up to +200 on all three nodes, this causes that all running VMs
are unaccessible. During this process oVirt event viewer shows some i/o 
storage error messages, when this happens random VMs get paused and will
not be resumed anymore (this almost happens every time but not all the 
VMs get paused).

During the event we tested the accessibility from the nodes to the 
storage and it looks like it is working normal, at least we can do a normal
"ls" on the storage without any delay of showing the contents.

We tried multiple things that we thought it causes this issue but 
nothing worked so far.
* rebooting storage / nodes / engine.
* disabling offsite rsync backups.
* moved the biggest VMs with highest load to different platform outside 
of oVirt.
* checked the wsize and rsize on the nfs mounts, storage and nodes are 
correct according to the "NFS troubleshooting page" on ovirt.org.

The environment is running in production so we are not free to test 
everything.

I can provide log files if needed.

Kind Regards,

Maikel