topic Re: msa2000 fc, mpio path problem? in HPE EVA Storage

msa2000 fc, mpio path problem?

marhag — Wed, 14 Apr 2010 17:43:47 GMT

Hello!

I'm having a MSA2012fc G1 (Dual controllers) connected to a couple of ESX-servers (ESX4 U1) with two HBAs via two SAN switches.

The servers sees only 2 paths to the storage, shouldn't it be 4?

The ESX-servers sees also something called LUN 0 (not presented to the servers). The servers says that LUN 0 is an Enclosure, the other LUNs are disks. What is this LUN 0 in the HP MSA2000 ?

The servers has 4 paths to LUN 0 but 2 to storage-LUNs.

Thankful for answers

Re: msa2000 fc, mpio path problem?

Marcus Schack — Wed, 14 Apr 2010 17:51:48 GMT

Well... I believe your ESX may already had the MPIO built in? So you wont see all four paths. Also dependent on how you have it zoned.

Re: msa2000 fc, mpio path problem?

marhag — Wed, 14 Apr 2010 17:55:50 GMT

It's zoned in one switch with one HBA of all ESX servers plus the MSA2000 in one zone.

And in the other switch all the other HBAs plus the MSA.

What about this LUN0 ?

Re: msa2000 fc, mpio path problem?

Marcus Schack — Wed, 14 Apr 2010 18:21:04 GMT

Normally you would put the MSA ports A1 and B1 into one switch and A2 and B2 into the other switch. The pattern would be the same for each server also.

Re: msa2000 fc, mpio path problem?

marhag — Wed, 14 Apr 2010 18:34:32 GMT

It's connected as it should be due to the product manual, and as you say - one cable from each controller to one switch. It's very important here that the right ports on the msa controllers are connected to right switch. The connections we have are confirmed by HP for a couple of months ago.

Re: msa2000 fc, mpio path problem?

Uwe Zessin — Wed, 14 Apr 2010 18:40:04 GMT

There are only two paths to storage LUNs, because the MSA2000 G1 series is basically two single controllers "bolted together" in a crude way. A single virtual disk with all its volumes is maintained by one controller, but there are no ALUA or even standby paths via the second controller available.

The "LUN 0" is used for SCSI-3 "REPORT LUNS" support and maybe for some in-band communication with the controllers.

Re: msa2000 fc, mpio path problem?

Marcus Schack — Wed, 14 Apr 2010 18:41:23 GMT

Thank you Uwe.. you are a fountain of knowledge :)

Re: msa2000 fc, mpio path problem?

Marcus Schack — Wed, 14 Apr 2010 18:42:40 GMT

So if he is seeing two paths, then MPIO needs to be loaded, I would assume.

Re: msa2000 fc, mpio path problem?

Marcus Schack — Wed, 14 Apr 2010 18:45:05 GMT

Sorry, he is running ESX. I understand that ESX has its own multi-pathing built in.

Re: msa2000 fc, mpio path problem?

marhag — Wed, 14 Apr 2010 19:01:57 GMT

Thank you. I'm very impressed with your knowledge Uwe!