topic Re: Changing SAN storage in Operating System - HP-UX

Changing SAN storage

mogiro — Fri, 23 Nov 2007 05:43:06 GMT

Hi,
I'm going to upgrade my old EMC storage system to a brand new model from EMC too. I want to take into account all the changes it will represent from a sys admin point of view, I mean, I know that with the change the HW path will change so, what steps I have to do to keep the data from the old system to the new one? The data from the old storage is going to be migrated to the new one throw SRDF (replication done by HW from one storage system to the other, without using the SO). The LUN´s configuration will be the same in the new one than in the old one, of course the new one has more LUN´s that will be assignated before the migration. The machine connected throw SAN switch to the storage is the main node of a 2 node´s Service Guard system (quorum disk?)using HPUX 11.11. I think I'm not forgetting any important data to understand what I need.
Thanks in advance for your answers!!

Re: Changing SAN storage

mmax — Fri, 23 Nov 2007 06:51:10 GMT

Hello.

In HP-UX 11.11 is adressing dependent on the connection of the storage to the SAN

Than if you will connect new array to same switch and same port, with the same LUN's presented to the same host you'll see same adressing from OS point of view like from old array.

For the migration of data it's common in LVM to use
vgexport -p -s -m mapfile -f outfile vgname

and for import

vgimport -m mapfile -f outfile vgname
or
vgimport -m mapfile -s vgname

check manpages before you'll apply this command

I recommend to use vgexport with -s option to save also your vgID information to outfile.

If you'll use vgimport with -s option this will automatically scan your dsk devices and where will be same vgid in the header it'll be added to imported vg. This will also change order of the PVs in the lvmtab what shoudl cause problem if you have pvgstrict policy...

BR

Re: Changing SAN storage

mogiro — Fri, 23 Nov 2007 11:09:24 GMT

Hi,
The storage is going to be connected to the SAN throw another switch port, so the adressing of the disks is going to change. In this case, additional tasks are required to the vgexport/vgimport?

Re: Changing SAN storage

Bill Hassell — Fri, 23 Nov 2007 12:37:37 GMT

This is the beauty of the vgexport/vgimport command. The mapfile and VGID (volume group ID, from the -s option) will be used to search out all the disks on your system for a match. Then the LUNs that report a matching VGID will be setup in the volume group, even though the LUN device file names did not match your previous volume group.

Re: Changing SAN storage

mogiro — Sat, 24 Nov 2007 19:17:10 GMT

Hi all again,
After 17 hours of work non stop (only a pizza...) we finally have changed the SAN storage.
For your information, as you said, using the same ports on the SAN switch and as the LUN's config is also the same, no additional changes had been necessary, the Service Guard package that activates all the vg's, starts the oracle DB and the SAP instances, has done its work successfully.
Thanks to all you for your information.

Re: Changing SAN storage

mogiro — Sat, 24 Nov 2007 19:21:11 GMT

Do nothing using the same SAN switch ports.