Powerpath and Veritas Volume Manager 1

[SuperJan]

Hi,

Upgrading our CX600 to CX700 this weekend.

I am also adding a Sun V880 server, running Veritas Volume Manager 3.2 on the internal disks to our SAN. I was told that I would have to disable DMP if I was going to use Powerpath.

Never done this before.....any advice on what to look out for and what might go wrong? EMC engineer will be on-site to assist, but I just wanted your expert advice before I started.

Thanks in advance

 

[Chacalinc]

don't do that... I have installed several CX in Solaris environment with Volume Manager.

DMP and PowerPath con live together... in fact, let DMP on in order to have only one instance of the LUN, with DMP off and powerpath running, when you issue "vxdisk list" you will see the same LUN twice or more times depending on how many paths you have to the LUN...

example: you have a SAN with 2 switches, server with 2 HBAs, so you connect:
HBA1 to swA:
HBA2 to swB:

swA to SPA0 and SPB0
swB to SPA1 and SPB1

zones on swA:
HBA1 with SPA0
HBA1 with SPB0

zones on swB:
HBA2 with SPA1
HBA2 with SPB1

As you can see, 1 LUN is showed to the server through 4 ports, so the solaris will see the same LUN 4 times!!! now, issue "vxdisk list":

* DMP off:
c3t0d0 error
c4t0d0 error
c5t0d0 error
c6t0d0 error

* DMP on:
c3t0d0 error

only one!! (and correct) powerpath will work with no problems with DMP on. You can see that giving work to the CX LUN and monitor with "powermt display dev=c3t0d0 every=2"

Hope this helps you.

Cheers.

 

[SuperJan]

Thanks for your advice....spot on

When the EMC engineer arrived on-site for the CX upgrade he said I could have DMP and Powerpath running as long as they were access different devices.

The CX700 is in and the V880 can see the san.

Thanks for taking the time to respond.

Regards
Janis