Poor NFS Performance: OpenFiler

[Stevester]

Good Day Everyone,

I have an issue with OpenFiler, a Linux-based operating that converts a computer system into a SAN/NAS appliance. Here is the problem. In my environment we have two Netapp Storevault 500 appliances that I normally perform backups to a NFS share. There are two backup cronjobs that use ghettoVCB to backup two groups of VM's. One group is a pool of 3 VMs. This takes 13 mins to complete. A second job that backups a pool of 5 VMs to a 2nd Storevault appliance which takes 2 hours.

We then installed Openfiler on a old server that has 2 core Xeon processors. There is a software RAID 5 process in place. When performing the same backups to a NFS Openfiler share, the first backup job, which takes 13 mins, takes around 4 hours. The second backup job, which takes 2 hours, takes almost 10 hours to complete. This is unacceptable!!!! Especially considering the strain placed on the host ESX Server. I assumed that because of the software RAID 5, the overhead on the CPU explained the long backup times.

I then installed Openfiler on a 2nd server, an IBM x306 machine which has a P4 Intel processor. This time no software RAID or any RAID at all. A single 750GB hard drive that contained the OS and the rest of the disk uses to backup VMs to a NFS share. I performed the first backup job of the pool of 3 VMs. This time the backup job took 1 and 1/2 hours to complete instead of 13 mins!!!!!!!!!!

Is Openfiler simply poor at being an NFS Server!!!!!!!!!!!!! Has anyone else had these issues with Openfiler?

Thanks

Steve

[vlho]

Hi Stevester,

you need use option async on NFS export

[Stevester]

How do you enable the async option on Openfiler?

Thanks

Steve

[vlho]

you click to Edit, see photo...

[Stevester]

Thanks!!!!!!!!! This worked. My completion time decreased from 90 mins to 23 mins. However I have another issue which I am going to address in another thread concerning Openfiler NFS datastore.

Stevester

[vmbru]

vlho,

Wondering, you have Write Delay set at "wdelay", guessing that is right mode when using ASYNC, we use ASYNC too but have it set at "no wdelay". Should we switch? (hoping yes to get better IO for VDR purposes) does it matter? Originally had Openfiler at SYNC and it did not update the Write Delay drop-down when we switched to ASYNC .

Thanks.

[vlho]

Hi wmbru,

The "wdelay" option has no effect when the "async" option is set.

You look e.g. here: http://www.redhat.com/docs/manuals/linux/RHL-9-Manual/ref-guide/s1-nfs-server-config.html

[vmbru]

Thanks!