Hi all
Hope someone can help, ran into a bit of a wall here. We're running ESXi 5.1 on an HP Proliant DL120 G7 and Intel Cougar Point 6 SATA controller, with 4 identical WD 2TB drives.
We've got 4 datastores configured, each on the 4 WD drives.
The problem is that uploading say a 2GB file via vSphere's datastore browser takes incredibly long (at least 20 minutes) on 3 of the 4 datastores, with the odd one out completing in under 2 minutes. I cannot for the life of me figure out what exactly is different between the datastores, especially considering that they're all using what should be identical backend hardware.
Just as a test, I'm seeing the same behaviour when I SSH to the ESXi host and copy something from one datastore to another - 3 of 4 datastores return write speeds of just over 9MB/s.
Reading up on the Cougar Point 6 controller though, apparently it has 2 6GB/s ports and 4 3GB/s ports, but there doesn't seem to be a lot of easily accessible info on it. I do not have the output immediately accessible, but all four disks are set at 3GB/s, so doubt that could have anything to do with it.
Apparently there was/ is also a hardware bug with the B2 stepping version of this particular controller, though I have no idea how to identify whether this controller comes from the faulty batch.
What I'm more interested in at this stage is if there's a recommended way of identifying where the bottleneck is via ESXi? I'm baffled why one datastore's performance would be great, while others notsomuch.
Any help appreciated.