The once trusty Openfiler storage modules had been playing up recently since the VMware infrastructure was upgraded from VI3 to vSphere; here are some fixes which seem to have done the trick in fixing the problems with LUNs locking up under high I/O.
1: Properties of the iSCSI Target (Volumes -> Target Configuration)
Make these changes to the default settings:
2: Unmap LUN and re-map (Volumes -> LUN Mapping) as write-back and fileio
3: Connect via SSH with root login and run this command
Note: the Openfiler box needs internet access and if need to go through a proxy then edit the file conaryrc in /etc, and put this line at the top with the relevant details:
Using Openfiler with Microsoft iSCSI Initiator:
If you are experiencing slow performance from a Windows Server connected to Openfiler using the Microsoft iSCSI initiator, the changes to the default iSCSI target settings outlined above will help.
We were using Openfiler as a temporary iSCSI storage device for the staging area for a large Exchange public folder restore. With the default settings - the performance writing to the Openfiler storage was very poor at 200 MB/min. With the modified settings -
ImmediateData = yes
MaxRecvDataSegmentLength = 262144
MaxXmitDataSegmentLength = 262144
R/W Mode = write-back
Transfer Mode = fileio
- we were getting a transfer rate of 2 GB/min across the 1 Gbps network.