Tag Archives: Reference

XIV <--> VMware LUN ID mapping

I have to dig far too hard to find this information anytime I want it, so I’m putting it here. I just one-lined a CSV file in PowerCLI to list all of my attached LUNs across my entire VMware environment (only 1 vCenter ┬ámakes it easy). Each LUN “CanonicalName” that is attached to an XIV array starts with “eui.00173800″ regardless of which array the LUN actually lives on. There are 8 hex digits remaining, of them it appears that first 4 are used to identify the array and the last 4 used to identify the LUN serial number.

Verifying that succeeds. I can see that the serial number of the XIV for which I have the most LUNs presented on shows up as the 4 hex digits numbered 9-12 in the euis in my list.

The last 4 don’t jive up initially when I look at LUN serial numbers, but that’s because I chose the very first one to look at, which is 0000 for digits 13-16. It appears that ESXi must create some sort of dummy LUN 0 for each array, all the following arrays make sense. It’s also worth noting that my RDMs show up in this list.

So the final number looks like this:

[00000000][1111][2222]
[IBM-XIV!][ARSN][LUN#]

In the real world if I have a LUN Conanic eui.0017380035bc001d it’s referencing an XIV array S/N 13756 (35bc hex -> dec) and the LUN S/N 29 (001d hex -> dec).

Last note, if you need this reference you probably already are aware of this and even noticed it in the example above, but in VMware land we typically use hexadecimal to reference storage addresses, by default though XIV GUI lists everyting (including array S/N) in decimal. It all has to be converted. The LUN Serial Numbers can be done right in the GUI under Tools>Management, but you’ll have to convert array S/N either by hand or in your head if you can hex like a boss.