topic Re: VXVM boot disk in Operating System - HP-UX

VXVM boot disk

Peter Marais — Tue, 04 Jul 2006 08:26:19 GMT

How do I replace a vxvm boot disk with a larger disk on hp-ux 11.23 Itanium? I need to extend the root and stand filesystems.

Re: VXVM boot disk

Mridul Shrivastava — Tue, 04 Jul 2006 08:35:25 GMT

If you need to extend root and stand filesystem isezes then the best way is to take ignite backup and then while restoring make changes to the sizes of root and stand.

Re: VXVM boot disk

Peter Marais — Tue, 04 Jul 2006 09:22:27 GMT

Thanks, using ignite means downtime. I would like to keep the system up as long as possible and reboot once onto the new disk

Re: VXVM boot disk

Mridul Shrivastava — Tue, 04 Jul 2006 09:34:06 GMT

It's not possible to make changes to the size of root/ stand without bringing down the server.
So create ignite backup and as and when new disk is available plan this activity. This would be best and safe way of doing this.

Re: VXVM boot disk

Peter Marais — Tue, 04 Jul 2006 10:13:12 GMT

Surely there is a way of duplicating the system disk onto another disk and then just rebooting to the new disk?

Re: VXVM boot disk

Patrice Le Guyader — Tue, 04 Jul 2006 10:52:46 GMT

hello peter,

You can use vxdiskadm to mirror the root disk.

You first choose option 1 to add the disk to the rootdg and then choose option 5 to mirror the volumes on the disk.

To do it through command line, try this.

1.) vxdisksetup -iB cxtydz (To initialise disk under Volume manager)
2.) vxdg -g rootdg adddisk rootdisk=cxtydz ( To add the disk to the Disk Group)
3.) vxrootmir -v -b -R cxtydz ( To create the mirror)

With cxtydz the mirror disk. I don't use it as system disk on HPUX, only on solaris so I hope it's enough to be able to boot on the mirror.

Hope this helps
Kenavo
Pat

Re: VXVM boot disk

Torsten. — Tue, 04 Jul 2006 10:58:07 GMT

"Surely there is a way of duplicating the system disk onto another disk and then just rebooting to the new disk?"

Of course you can *duplicate* the disk, but the size of stand and root will be the same!

To increase it, you should use ignite, backup your data, adjust the values and restore.

Re: VXVM boot disk

Peter Marais — Wed, 05 Jul 2006 01:24:28 GMT

Thanks Patrice, HP-UX has a command vxrootmir which will create a bootable backup of the system disk for you. Using vxbrk_rootmir you can separate them again and you have two copies of the root disk. The trick is /stand and root are contiguos so you cannot just expand them without making space. I have the procedure to create a boot disk with LVM but not with VXVM and I know it can be done. Is there no one out there that has done this before and documented it? Besides using Ignite backup.

Re: VXVM boot disk

Mridul Shrivastava — Wed, 05 Jul 2006 02:09:47 GMT

I never came across a way that talks about increasing root and stand without rebooting the server once.... ( either it is LVM or Vxvm)...

There are lots of conditions if they met then it might be possible to increase, like if there is some space available between stand and swap then stand can be increased to that size.

Else the other way is to boot in lvm maintenance and then remove swap increase stand then recreate swap...

You told us that you have procedure of it doing with LVM, could you please share it with us.....( I have never seen such a doc).

Re: VXVM boot disk

Peter Marais — Wed, 05 Jul 2006 02:53:51 GMT

I am prepared to reboot the system to the newly created larger disk. Remember we are working with VXVM here. The procedure to do it on LVM you will find at:
http://h21007.www2.hp.com/dspp/tech/tech_TechSingleTipDetailPage_IDX/1,2366,5343,00.html

This will tell you how to mirror a disk. To modify the filesystem size I attach a file.