Moving ES80's attached to EVA

[Aaron Lewis]

I need to rearrage my datacenter a little bit. I have a pair of ES80's that are attached to a pair of EVA3000's. I just heard, that if I disconnect the Fibre Cables from the ES80's I will need to re-establish all my WWID info, and re-define all my current paths. Has anybody experienced this? Anyway to prevent this from happening?

[Uwe Zessin]

Aaron,
you only need to reconnect the cables to the same switch ports as before - then everything will continue working.

Do you inted to do any changes together with the move?

[Aaron Lewis]

not planning any changes, just have a short window to accomplish the moves. If WWID & path info gets wiped out I may not have the systems back up in time.

[Uwe Zessin]

Well, you can save them in case the AlphaServer console looses the setting, but then you are in trouble anyway:
>>> show boot*
>>> show device
>>> show N*
>>> show wwid*

[Mike Naime]

Aaron:

Unplugging and re-plugging a cable has no effect on the SAN path, or availability of the storage to your alphaserver. Whoever told you this needs more SAN education. If you label your cables and adapters prior to unplugging anything, you should not have any problems after everything is plugged back in.

Potential gotchas are in the Alphaserver and SAN switches more than the storage controller.

The EVA Keys off of WWID of the ports for the host that you defined on the SAN appliance. This information will not change until you get on the appliance and change it. (You are safe here!) It doesn't matter which port that WWID comes in on the EVA, it will present out your LUNS to the host reguardless of what port that particular WWID is seen on.

IF you swap the cables, your boot parameters will change (Swapped)


1.) Did you Zone your SAN switches? If you did, Did you use hardware port zoning, or did you use WWID zoning. If you used WWID zoning, then swapped cables will mean that you do not see any storage at all. If you used port zoning, then you will be OK.

If you used hardware port zoning, AND you swapped your cables, your paths to the EVA have changed in that the PGA adapter now has the two ports that PGB used to have. You would have to run WWIDMGR to reset your boot LUN paths, or swap the cables to fix it.

If you did not want to swap the cables, here is what you would have to do to fix your Alphaserver boot parameters.

SHO BOOT* (Note the LUN # of the boot LUN)
INIT
...
WWIDMGR -clear all
WWIDMGR -quickset -udid {LUN#}
{you should get confirmation of 4 paths here}
INIT
...
set bootdef_dev dg*{lun#}.*.*.*.*
set dump_dev dg*{LUN#}.*.*.*.*
SHO BOOT*
SHO DUMP*
{Ready to boot!}


To sumarize. Do your move. Try to boot. If it fails, swap your Fibre cables. Now you should be able to boot.

Mike Naime