ERROR: VMware ESXi with 3PAR SAN and Dead LUN 254

Problem

Last week I discovered  a couple of error messages in the vmkernel.log file that caused me some concern:

2012-06-22T18:18:45.806Z cpu17:939673)WARNING: vmw_psp_rr: psp_rrSelectPathToActivate:972:Could not select path for device "Unregistered Device".
2012-06-22T18:18:45.806Z cpu17:939673)WARNING: NMP: nmpPathClaimEnd:1195:Device, seen through path vmhba2:C0:T2:L254 is not registered (no active paths)

I did a "esxcfg-mpath -l" and found 4 dead paths - 2 to each fibre HBA.  I never provisioned a LUN with an ID of 254.  Maybe this was a "special use" LUN?  I doubted it because my HP EVA has one of these and the device is listed in vCenter.  However, there were no devices with LUN ID of 254 listed anywhere in vCenter, only 4 dead paths.

Solution

After a focused Google search, I found the answer.  The HP 3PAR guy that came out and did the installation had us use a host persona of "1 - Generic" when we should have used "6 - Generic-legacy".  Luckily these can be changed on the fly via the InForm Management Console.

After making the change in the IMC, I rescaned each of the hosts and the messages stop appearing in the vmkernel.log and the dead paths were no longer listed in the vSphere Client.

Here are the relevant sites I found per the Google search:

Fix - 3PAR with VMware- LUN 254 Dead

3PAR/VMware LUN 254 Dead???

And, of course, I always recommend following the manufacturer's best practices:

HP 3PAR VMware ESX Implementation Guide

Looks like the guide was recently updated and it does recommend using the persona of "6 - Generic legacy".

Another mystery solved.

VMware ESXi and HP 3PAR Storage

We recently added a new HP 3PAR F400 SAN to our existing VMware cluster.  If you haven't read about this SAN and are interested in SAN storage, I highly recommend you take a look at HP's site for more information: 3PAR Storage.

One thing I've found this SAN lacking in is documentation.  It's easy to find, but bits of information are scattered across several documents.  The HP implementation consultant handed me a thumb drive with 3GBs of data before he left, half of which are PDFs (to give you an idea).

The point of this post is to bring all of these bits together in one place to include settings and best practices for VMware ESXi 5.0 along with the relevant references.  Here's what I've found so far - I will continue to add and update settings as I find them where relevant:

ESXi Advanced Settings:

DiskMaxIOSize   = 128 (Source)
QFullSampleSize = 32  (Source)
QFullThreshold  = 4

Default Path Selection Policy (PSP) = VM_PSP_RR (Source and Powershell Tip)

IOPS = 1

LUN Size = As large as ESXi can handle, currently 2TB (Source)

VMDK format = Eager Zeroed Thick

VMs - zero-out free space (Source):

   For Windows = SDELETE (Download)

   For Linux = DD  (section 3.2.1 in source doc linked above)