SAN migration with VxVM

[David Child_1]

Hello all,

I have done many migrations between storage frames on HP-UX servers using LVM in the past, but I now find myself in need of migrating several HP-UX servers using VxVM from one EMC frame to another.

The frame migration is taking place using SRDF.

The servers are all HP-UX 11.11 and are using the base VxVM product.

My initial thoughts on migrating were as follows;

1) stop all applications on the servers and unmount the file systems
2) wait for the SRDF adaptive copy to finish copying all changes
3) vxdg deport dgname
4) ioscan;insf;vxdctl enable
5) suppress the paths to the original LUNs in VxVM
6) vxdg import dgname

If all checks out okay we clean up the old device files, etc.

Note: at the time of the cut-over the servers will see both frames.

I could be way off base here so any assistance/feedback would be greatly appreciated. I'm going to dig into the documentation now to see what I can find.

Thanks,
David

[Hasan Atasoy]

hi david;
one concern is for the last step,
if both volumes will be visible to the same server at the end step it will be problematic. because both original and r1 copies have the same vx header in the disks .

my action plan a bit different for you.

0) server see just original disks.
1) stop all applications on the servers and unmount the file systems
2) wait for the SRDF adaptive copy to finish copying all changes
3) vxdg deport dgname
3a) unpresent old disk and present new ones.
4) ioscan;insf;vxdctl enable
6) vxdg import dgname

Hasan.

[Tim Nelson]

Not that this answers your question, just different experience.

In the past I did not rely on EMC and/or the extra expense to move my data. I simply presented the new storage to the server and used Mirror/UX to migrate the data from one frame to the other. Simple, smooth, no errors in low impact environments this can even be done online during the day.

Something else to think about although you would have to mirror through VxVM.

[David Child_1]

Hello Hasan,

I understand what you are talking about. That was why I was going to perform step 5 (suppress the paths to the old disks). I figured that would hide the old paths to the disks and therefore only use the new ones. I will check with the storage team to see if they will be able to remove access to the old frame as you suggest.

Tim,

Yes, I have done migrations in the past as you mention. We unfortunately have a separate group that handles all the storage and this project was well underway before we were informed/involved. Thanks for the tip though.

David