Split of /dev/vg00 mirror to enable HP-UX upgrade

[Nick Sopowski]

I have a K370 system running HP-UX 10.20 and I am looking at splitting off the mirrored copy of /dev/vg00 so that I can upgrade to HP-UX 11.0 and retain HP-UX 10.20 on the other disk in case of the need for a speedy regression.
I have seen several notes in the forum where this has been asked before but can anyone say what the best method is ?? i.e lvsplit or lvreduce .
How difficult / easy is this to achieve ?
Any tips would be most welcome !

[Ajitkumar Rane]

I would suggest the best and easiest is to use the lvreduce method for an OS upgrade.Normally we lvsplit the vg00 for patch updates.For OS upgrade you would be destroying one of the copies of the OS disk.This will cause a little problems in the future when you decide to go back to 10.20 because lvm will reference the disk for which the lvm structures for 10.20 has already been destroyed by loading 11.0.

I hope this helps.

Good luck

[Ted Ellis_2]

In either case, make sure and run a recovery tape with the Ignite/UX utility before starting. We had a mirror corruption that was recently saved with this.

[Andre Machado_1]

Hi Nick,
If you want to INSTALL HP-UX 11.00 in one disk and you want to make the other disk with HP-UX 10.20 to Backup, this is answer for your ask:
1. Verify the disks to install:
cXtXdX -> primary disk for VG00
cYtYdY -> mirro disk for VG00

2. Execute the install on disk cXtXdX, normal
boot to CDROM and install, select disc
cXtXdX to install HP-UX

3. After install you must execute this steps
to split discs:
# mkdir /dev/vg_old
# mknod /dev/vg_old/group c 64 0x010000
-> make sure you haven't minor number
0x010000 configured in your system.
# vgimport /dev/vg_old /dev/dsk/cYtYdY
Errors occurs, the will inform you have 2
disks ... bus command is complet.
# vgchange -a y -q n vg_old
Erros occurs, but vg wil activate

- Now you must be split mirror
# lvdisplay -v -k /dev/vg_old/lvol1

--- Logical extents ---
LE PV1 PE1 Status 1 PV2 PE2 Status 2
00000 0 00000 stale 2 00000 current
- Take the number of PV whi the "stale" status, called PV_Key

# lvremove -f -k /dev/vg_old/lvol1 0
- execute this command for all lvols of VG
# lvremove -f -k /dev/vg_old/lvol?? PV_KEY

- After this commands you is able to boot up disc cYtYdY with HP-UX 10.20 or disc cXtXdX with HP-UX 11.00.

Sorry my bad english!

Best regards,

Andre Machado

[Sandor Horvath_2]

Hi !

Make backup first and do vgcfgbackup

change AUTO file in LIF( extend with -lq ) in Your primary disk. It is need for boot if disk missing.

Install new HP-UX to the secondary disk.

Backup old to old system use vgcfgrestore and vgsync, or if new system is OK make mirror it.

regards, Saa

[Nick Sopowski]

Thanks for the replies so far !
I thought it would be a good idea to just split off one of the disks in /dev/vg00 and have it sit there ready incase I needed to regress back to 10.20 in an emergency ,i.e customers applications do not run correctly at 11.00, however, after reading the replies maybe I had a too simplified view of what I wanted to do !.

Anyhow ,after reading through the replies and doing some searching , I think a straight update to 11.0 from 10.20 using the Ignite-UX `recovery tape` procedure for regression will possibly be a better solution.

I would have liked to experiment but unfortunately I do not have that luxury !

[Dave Wherry · Accepted solution]

Nick,
I suggest you use the split mirror method. I used it and it worked very well. It allowed me to practice the upgrade before actually doing it. Did this several times and was always able to boot from my 10.20 disk. I was also able to do it in phases. I split and booted off of the mirror. Did some work. Rebooted off of the primary and let normal jobs run over night. Went back the next day and booted from the mirror again. Continued with upgrade work.
Search for document ID X1401978, it details the procedure.

[Peggy Fong]

I hope it is not too late to post my 2cents worth. I came from a shop that had 300 Tclass, V, N, D, etc etc. When we did new os installs we always reduced out the primary disk so that the 10.20 os was running on mirror disk but now there are no mirrors. We made sure we could boot our os from that disk. Then we installed (or used Ignite-UX) to the now unused primary disk. Once we booted from the new 11.X disk we could import the old 10.20 disk (we would name it /dev/vg10.20 for example) and have access to the root files (/, /usr, /opt, etc) which made it very simple to copy over the files unique to that system. And the best part was we could always boot back to 10.20 for a quick recovery or to continue the work at a later date.

Note: you can also import the 11.x disk while booted from the 10.20 disk (just give it a different vgname.) When satisfied that the new OS works, simply remove the 10.20 volume that you vgimported while booted on the new disk. Then mirror your vg00 disk to the 10.20 disk. If you want more detail I'd be happy to provide them - email me at pfong@mwd.dst.ca.us or pegz@wwdb.org