LUN ID question

[rz1]

I was under the impression (and I don't recall from where at this point), that within a cluster, the LUN number that is displayed under the Configuration tab -> Storage Adapters -> Fiber Channel device details, needed to be unique for each of the LUNs listed. We previously only used EMC storage and would set the LUN id to a unique number when presenting the storage to all the ESX hosts within the cluster (even if it was from two different EMC arrays). We're now adding a different vendor's SAN to our environment and I'm wondering if this is a valid concern. For example, if within the "Devices" view, is it ok to have multiple LUN 0's listed since the "Runtime Name" is unique in each case?

Thank you...

[AndreTheGiant]

LUN ID may be different on storage side and ESX side.

Each storage has his own LUN IDs, and on different storage can also be the same.

Each ESX has his own LUN IDs.

Only for RDM disk may be important to have same ID on all ESXs.

To be sure of that you can simple present LUNs in the same sequence on all your hosts.

Andre

[a_p_]

It's the same with other storage vendors, too. Always assign a LUN to all ESX hosts with the same LUN-ID. Actually this is not only for ESX, the same applies to e.g. MSCS.

Take a look at VMware KB Identifying disks when working with VMware ESX for details.

André

[zyyang]

Hi Andre,

You mentioned that

"Only for RDM disk may be important to have same ID on all ESXs.

To be sure of that you can simple present LUNs in the same sequence on all your hosts"

I actually have the issues of RDM disk sharing.

I have four esxi hosts(A, B, C, D) in a single vSphere environment which all connect in a clarrion storage. Each esxi host can identify all LUNs(15 LUNs in total) in the Clarrion and generates the same LUN ID. However, the LUN sequences in each esxi are not the same. The following lists the LUN sequences of each esxi host:

A: 5, 4, 7, 13, 6, 14, 2, 12, 8, 11, 0, 10, 9, 1, 3

B: 4, 3, 6, 12, 5, 14, 2, 13, 7, 8, 0, 9, 10, 11, 1

C: 8, 0, 3, 12, 1, 14, 2, 13, 4, 9, 6, 10, 11, 5, 7

😧 4, 3, 6, 12, 5, 14, 2, 13, 7, 8, 0, 9, 10, 11, 1

Actually, host B and D have the same LUN sequence, so RDM sharing is OK. But for other hosts,....

So my question is that :

How could I configure each esxi host to present LUNs in the same sequence? Could you give me some advice to solve the problem.

Thanks!