Migrate EMC to XP512

[Matrah]

Hello ,
Here my probleme : I have to add Fibre Channel Card ( A5158A ) in N4000 class.My servers are already connected to a EMC2 array disk.I need to remove only one of my old FC card unless to change the instances.
If i add my new card,did i find after the reboot the same instances of my disk that i had with the old card ? ( defore : c3t2d1 ; after c??t??d?? ).

Thanks for help.

[Animesh Chakraborty]

hi,
Are you using EMC volume logix ?
The wwn(world wide number)is unique for each fc card.Volume logix determines ,by the hba's wwn,which hosts can access which volumes.
After you replaced the fc card,you need to use emc's fpath command to incorporate new wwn.
your c?t?d? will remain same.

Thanks
Animesh

[Matrah]

I must to know , if after to add A5158A FC, my disk whitch it called c3t2d2 will be see by the system (after adding the FC) c3t2d2 ?
Thanks.

[Santosh Nair_1]

If you're just swapping out an old FC card for a new one in the same slot, I don't believe the instance numbers change, so the disks should be the same devices. However, each FC card has a unique WWN (as mentioned by Animesh) and so you must reconfigure the EMC to tell it the WWN of the new card.

-Santosh

[Matrah]

I have remarqued when i add a new card FC (A5158A) in a N class, all the instances ok my disk changed.

[Santosh Nair_1 · Accepted solution]

Just as a precaution, I would create a map file for all the volumes on that controller. This way, you could always re-import the VG even if the control does change.

for VG in
do
vgexport -s -p -m $VG.map $VG
done

Then, if the controller instance changes, just vgimport -s -m $VG.map $VG after vgexporting the old $VG and recreating the $VG dir and group files.

-Santosh

[Matrah]

It's a solution Santosh, but i have 96 disk with critical data on it.
Is there an other way to performe It ?

[Carlos Fernandez Riera]

NO.

It is not posible. Disk driver are composed of tree parts ( you know).CxxTxxDxx

Dxx and Txx are setting on EMC or XP side.

Cxx are setting with Hardware Path, and this is unique for each card on your box.

[Carlos Fernandez Riera]

I reread the question and now i dont know if your are planning to change or to add a new card.

Last time i changed connections to my EMC, it changed most of my disks ( c11-> c18 ..).

Vgexport -s -m found again all my vgs. It took same minutes but in facts it was a easy way.


Regards.

[Santosh Nair_1]

You could write simple script to do the export and import, but basically, there is no simple way to do this. In any case, this is just a precautionary step.

-Santosh

[Matrah]

Carlos , you explain me to use vgexport and vgimport with 96 disk.OK but It's not dangerous ??

[Santosh Nair_1]

Well for one thing, you're doing the vgexport with the -p (preview) option, which does NOT actually export the VG, so its fairly safe. Also, even if you had actually exported the VG, the data is still does not get touched...only the VG information on the system, but since you have a map file, you should be able to restore the VG info fairly easily by doing a vgimport.

-Santosh

[Carlos Fernandez Riera]

No, at all. It is a secure way.

Vgexport -s include VGID into mapfile. Check it . vgexport -s -p -m /tmp/vgxx vg00.

Then vgimport -s -m will read that VGID and search all disks looking for this VGID, ... and automatic :), and adds all Alternate paths for each disk.

VGID is recorded in each disk:

dd if=/dev/rdsk/cxtxtx bs=1024 skip=8 count=9 | dd bs=8 skip=2 count=1 | od -x | head -1 .

Check it , try it , use it.

[Dave Wherry]

Could you clarify the question? Your subject is "Move EMC to XP512". No one has addressed moving the data. No matter what you do with a new FC card or vgexport and vgimport, your data is still physically on the old EMC.
It sounds as if you want to add another card and connect it to your XP512. If so, do that. Then you will have these new disks available to your host.
As for moving the data you can add these new XP disks into your exising volume group if the volume group can accept that many new disks. You said you have 96 now. To add a complete new set would require max pe to be 192 or higher.
Then mirror your existing logical volumes to the new disks. Once they are synced break off the old disks from the mirrors and remove the old disks from the volume group. Your data is moved from the EMC to the XP.