Yesterday as part of our ERP upgrade project I thought I would pilfer some of the new kit Dell has sent us, namely a MD3000i and a Poweredge 2950 and setup a ESXi enviroment. This way I can quickly deploy the new version of our ERP so the developers have something to work with while we get the real environment sorted out over the next couple of weeks.

Now I gotta admit this took wayyyyyy longer then it should of, ie 4 hours instead of 20 minutes. As with most things in IT there are some gotcha’s you have to be aware of, and wow did I find a gotcha. After an hour of frustration I was beginning to swear at Dell and the MD3000i as I was blaming it for the slow progress, I must have reconfigured that sucker a dozen times. Then I got a bum steer from a mate that told me the MD3000i needed it’s out-of-band management port in the same subnet as the iscsi ports to handle the chap… wrong!!!

With that I decided to fire up my trusty opensuse notebook, and within 10 seconds I had it connected to the iscsi lun I was presenting from the MD3000i. This was a WTF! moment.

At this point I was scratching my head and started swearing about ESXi, so I reconfigured it again, same result the MD3000i was seeing it’s SW initiator, but ESXi was not seeing the lun I was presenting it… this is where the God of IT “Google” steps in and I happen to come across a forum almost unrelated to my issue but in one of the threads I see a post from a guy complaining that ESXi unlike ESX won’t see a lun with a size greater then 2TB.

In ESX it’ll see the lun but you can’t format it from storage management as vmkfs has a 2TB limit, in ESXi the lun simply doesn’t appear. So the second I went back into the MD3000i and mapped a lun less then 2TB to ESXi it came up, previously I was presenting a 6TB lun. This has be kinda bummed as I wasted a fair chunk of my time on a simple gotcha, and while it’s my fault for not reading *ALL* the documentation on ESXi, I had read the Dell – VMware guides plenty in the 4 hours and none of them mentioned this.

I will hope and pray VirtualBox can mature and develop a nice bare metal hyper visor as well. As an aside the Dell MD3000i works like a charm, I have since tested it with VBox, VMware Server 2.0 and it plays nice there and no lun size issue.