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MSA1000 and multipath

 
Babak Haghtalab
Advisor

MSA1000 and multipath

Hi
I have one MSA1000 with two I/O module connect to two seperate external san switches.I have connected two blade 20p g3 servers with Mezzanine HBA crads ( with two port on each mezzanine card) to these san switches. I also used "Selective Storage Presentation" in ACU to presents some LUNS to these two blade servers.
I have attached the related diagram of the cluster .
Now the problem is when I disconect one path ( by turnning off one san switch or taking out the FC cable ) the redudant controller will not work and my cluster will get down .
Does any body knows what's the problem . I expect that MSA1000 fail over to the second controller without any user intruption.
Please help me out in this regard.
Thanks
6 REPLIES 6
Marek Nelec
Honored Contributor

Re: MSA1000 and multipath

You need proper multipath software for your OS. If you use Windows it would be MPIO (multi path I/O) basic DSM (device specific module) for MSA1000.
Babak Haghtalab
Advisor

Re: MSA1000 and multipath

I have checked with Secure Path and MPIO.But it seems that problem is some where else. May be at the MSA controllers!!??
Uwe Zessin
Honored Contributor

Re: MSA1000 and multipath

The MSA will not do a failover on its own when the active controller looses SAN connectivity. That is the job of the multipath software.

Have you made sure that all servers 'see' both controllers and the logical disks on both paths? I usually use the adapter BIOS to verify.

I would also double check, if the proper profile is set on the connection objects.
.
John Kufrovich
Honored Contributor

Re: MSA1000 and multipath

Babak can you supply a MSA cli >show tech_support
Babak Haghtalab
Advisor

Re: MSA1000 and multipath

I can see all the luns from my servers.
the luns relating to the passive controllers cannot be initilized in the diskmanager of windows.Whne I install Secure path or MPIO the second luns is disapeared.
John Kufrovich
Honored Contributor

Re: MSA1000 and multipath

Babak,

Great,
Let me clarify one item in your last statement. Both LUNs are still there. It is multipath software that mask this information from the OS and is responsibe for determining the correct path. To the OS, the OS see's one path, but multipath see's both paths