Mirror HDS to EMC (data migration)

[Leon Kazakin_1]

All,

I am about to migrate data from Hitachi array to EMC SYM using LVM mirroring.

Here's my plan and I hope you could review and point out any potential problems.

I have HP-UX 11.0 N-class attached to HDS by 4 HP Tachyon TL/TS Fibre Channel Mass Storage Adapters /dev/td[0-4].

I need to map those to the disks, so I can disconnect one of them and connect to EMC.
How do I do that?

I plan to do all of this on-line - no reboots or user interruption.

- allocate volumes on EMC at least the same size as existing PVs in my 8 VGs (one PV in each).
- install EMC agent on the server
- id HBAs that will be disconnected from HDS and connected to EMC.
- I remove PV links associated with those HBAs (vgreduce)
- HDS FC disconnected from the server (I consider doing it before vgreduce, so if I make mistake identifying the disks I don't kill the data)
- EMC FC cable connected to the server
- configure SAN zoning
- new disks discovered by HP-UX (ioscan -fnC disk ; symcfg discover)
- pvcreate on new disks
- new disks added to existing Volume Groups (vgextend)
- existing Logical Volumes mirrored using new disks (lvextend)
- verify that the mirror process's complete successfully (all extensions are in sync)
- verify data integrity (application run)
- remove mirrors (old disks) (lvreduce)
- remove old disks (PV links) from VGs (vgreduce)
- remove devices?
- disconnect remaining FC going to HDS.
- connect second FC to EMC, discover devices, add as PV links to VGs to create redundant path

I attach ioscan output.

Thanks,
Leon

[Steven E. Protter]

Plan seems reasonable.

You can use lvsplit to break the mirrors once you have verifited the new mirrors work.

I'd think about that versus lvreduce, don't know how that part of your plan would work out.

SEP

[Gerhard Roets]

Hi Leon

Just be sure to disable bad block re-alocation as this is a requirement for the EMC. I do not see it specifically specified in your plan.

Regards
Gerhard