topic Re: URGENT: renaming volume group in Operating System - HP-UX

URGENT: renaming volume group

Saulius_1 — Fri, 08 Nov 2002 06:11:41 GMT

Sorry for capitals, but I'm in the very bad situation as system admin. I have allready installed and running production application on the borrowed disks, which resides on /dev/vg02. Now we bought our own disks (actually it's array accessed through FC HBA), and we need somehow replace theese borrowed disks with our ones.
How to move data I understand, but how to "rename" /dev/vg03 (our disks) to /dev/vg02 (assuming that we remove all physical disks which provide PE for all LV in vg02). Note that destroying data in vg02 is not acceptable :(.
The worst thing, that I have no expierence with HPUX (two months or so)

HELP! :'(

Saulius

Re: URGENT: renaming volume group

Michael Tully — Fri, 08 Nov 2002 06:21:53 GMT

The only way you can actually rename a volume group is during the vgimport process. You can't *just rename it*.

If you going to create /dev/vg03 and copy the data, why do you need to need to rename it (vg02) at all.
Once you have migrated everything across to the new volumes and are satisfied with the new set up, all you have to do is a vgexport of /dev/vg02 to remove it and the disks from your system.

Re: URGENT: renaming volume group

T G Manikandan — Fri, 08 Nov 2002 06:34:12 GMT

check these hp doc
http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000062937554

http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000062683936

Re: URGENT: renaming volume group

T G Manikandan — Fri, 08 Nov 2002 06:35:43 GMT

check these hp doc
http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000062937554

http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000062683936

Re: URGENT: renaming volume group

T G Manikandan — Fri, 08 Nov 2002 06:37:01 GMT

check these hp doc
http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000062937554

http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000062683936

Re: URGENT: renaming volume group

Saulius_1 — Fri, 08 Nov 2002 07:17:54 GMT

The main problem is, that software is using informix database, which is using partitions of type RAW. I have no idea, how DB accesses these partitions, and I have bad suspicion, that they are accessed like /dev/vg02/lvol554, not in some wise way :(.
So I plan to copy everything when informix is down, and to start informix "like nothing changed". What do you think ? Is it possible NOT to configure application (it's third party one, not ours), and to change those damn disks :(.

Re: URGENT: renaming volume group

Saulius_1 — Fri, 08 Nov 2002 07:23:49 GMT

What about data consistency when doing vgexport/import ?
Do these commands affect any side user data ? Or it's only system tables under /etc/ dir change.

Re: URGENT: renaming volume group

Elif Gius — Fri, 08 Nov 2002 07:56:46 GMT

Hi Saulius,

you should not worry...vgexport/vgimport will not impact your data in your vg...
But keep a backup of your system ;-)

- create a new mapfile
vgexport -p -m /tmp/vg.map /dev/vg02
- shutdown your database
- umount the filesystem
- deactivate the vg
vgchange -a n /dev/vg02
- then edit your mapfile (replace the vgname)
- create "new" /dev/vgnewname
- do mknod and so on
- now vgimport:
vgimport -m /tmp/vg.map /dev/vgnewname /dev/dsk/cxtyd0

- if you have many disks you can use an insertfile where you entry all your disks

vgimport -m /tmp/vg.map -f infile /dev/vgnewname

- then mount your filesystems
- start your database

Good luck!

Re: URGENT: renaming volume group

Saulius_1 — Fri, 08 Nov 2002 08:04:36 GMT

Thank you all for you answers, I hope you have saved my sleep :), because I will try to do everything in practice. The best thing is, that I have found mapping of informix database <-> disks, (there are links in /dev). So vg renaming is not so crucial.

Re: URGENT: renaming volume group

Gerhard Roets — Mon, 11 Nov 2002 08:13:05 GMT

Saulius

It is important to know how to copy the raw volume. You should check your informix manuals. You would propably use the dd command to do it. Just be sure to find that out.

Regards
Gerhard

Re: URGENT: renaming volume group

Dave Wherry — Mon, 18 Nov 2002 15:56:57 GMT

I know I'm a little late, I've been out of town.
If you have MirrorDisk/UX you could have added the new disks into the existing volume group. Mirrored your logical volumes to the new disks. Decremented the mirrors and removed the old disks. This could all be done on-line.
If you do not have MirrorDisk, could Informix do the mirroring? I know you can with Oracle.

Re: URGENT: renaming volume group

Saulius_1 — Tue, 19 Nov 2002 05:30:47 GMT

Thanks for reply. I have already migrated to the VA7400 (forum info was VERY helpfull).
However I will keep in mind that MirrorDisk utility exists and might save my sleep ;).