We have two physical hosts (256GB RAM/dual 14 core processors/SSD's etc) both connected to an MD3800i using multipath (set up with the Dell storage software).
So from both physical hosts I can read/write from/to the MD3800i at 1GB/sec, no problem - it performs great.
We are wanting to set up Hyper-V CSV and run virtual machines in this CSV. I create the LUN and quorum and present to both hosts. Both hosts now have c:\ClusterStorage\Volume1\ as the LUN on the SAN. So far, so good...
I can copy a 9GB file in around 5 seconds to this C:\ClusterStorage\Volume1\ directory. I can also read 9GB in around 5 seconds by copying it from C:\ClusterStorage\Volume1\ to C:\. Again, all good and expected performance.
Then comes the issue. If I copy a 9GB file (9GB is just an example, it can be any size) from C:\ClusterStorage\Volume1\ to C:\ClusterStorage\Volume1\ it takes 25 seconds.
I then come over a feature on the MD3800i called ODX which should offload all iSCSI traffic onto the SAN (thus treating it like a local file copy on the SAN) instead of the server having to read the data, to then write it back. I am running the latest firmware, I have run smcli and executed "set storageArray odxsetting = true;" I have also checked it is enabled on the host OS by doing the following:
Set-ItemProperty hklm:\system\currentcontrolset\control\filesystem -Name "FilterSupportedFeaturesMode" -Value 0
As it takes 25 seconds for 9GB, I can only presume at this point that ODX isn't actually working, even though it's an advertised feature on the MD3800i product page.
As you can imagine with this poor performance, when we create a virtual machine in the CSV, local disk performance within the virtual machine is degraded massively and can consistently local file copy around 20MB/sec which is unacceptable.
How can we properly get ODX working on our MD3800i for CSV (I presume that's what the issue is here)? It clearly isn't an issue with the SAN or accessing the SAN else we wouldn't be able to copy or read a 9GB file in around 5-7 seconds (disk benchmark programs also show around 1-1.2GB/sec transfer speeds in both directions).
Many thanks for any help you can provide.