topic Re: Mirror root disk in Operating System - HP-UX

Mirror root disk

Robert Barton — Fri, 30 Mar 2001 17:44:26 GMT

What is the quick and easiest way to mirror the root disk. I have read serveral procedures and all seem long and drawn out. I was looking at the mirror question in today's forum and was wondering would sam do it all for me or would I still need to make a bootable LVM disk first.

Re: Mirror root disk

Mark Mitchell — Fri, 30 Mar 2001 17:49:55 GMT

sam will set it up with easy, but you have to tell the OS that the second disk is a boot disk and that you can use it without quarem. It seems drawn out but its rather quick process.

Re: Mirror root disk

Thierry Poels_1 — Fri, 30 Mar 2001 18:05:22 GMT

Hi,

I don't believe that SAM would help you to make a boot disk, not sure, but anyway.

[adapt the commands below to your needs]
Step 1 (before assigning anything to this disk!)
# pvcreate -B /dev/rdsk/c2t8d0
# mkboot /dev/rdsk/c2t8d0
# mkboot -a "hp-ux -lq(;0)/stand/vmunix" /dev/rdsk/c2t8d0

Step 2 (add the disk to VG00)
# vgextend /dev/vg00 /dev/dsk/c2t8d0

Step 3 (mirror the required lvols to this disk)
# lvextend -m 1 /dev/vg00/lvol1 /dev/dsk/c2t8d0
# lvextend -m 1 /dev/vg00/lvol2 /dev/dsk/c2t8d0
# lvextend -m 1 /dev/vg00/lvol3 /dev/dsk/c2t8d0

Step 4 : mirror the other lvols which you want/need to mirror.

Step 5 : try to boot from this disk :)
good luck,
Thierry
(don't blame me for any typo's ;)

Re: Mirror root disk

Mark Mitchell — Fri, 30 Mar 2001 18:19:24 GMT

Here are the steps
1 Make the disk a boot device
pvcreate -f -B /dev/rdsk/c0t8d0

2 Add the disk to the root VG
vgextend vg00 /dev/dsk/c0t8d0

3.Copy boot programs to the disk
mkboot -l /dev/dsk/c0t8d0

4. Make sure lif programs were added
lifls /dev/dsk/c0t8d0

5. Make sure that you mirror each lv in order
lvextend -m 1 /dev/vg00/lvol1
lvextend -m 1 /dev/vg00/lvol2
lvextend -m 1 /dev/vg00/lvol3
lvextend -m 1 /dev/vg00/lvol4
lvextend -m 1 /dev/vg00/lvol5
lvextend -m 1 /dev/vg00/lvol6
lvextend -m 1 /dev/vg00/lvol7
lvextend -m 1 /dev/vg00/lvol8
lvextend -m 1 /dev/vg00/lvol9

6. Verify mirrors are correct
lvlnboot -v vg00

7.Copy the auto file used by hpux loader at start up
lifcp /dev/dsk/c0t5d0:AUTO -
then enter
lifco /dev/dsk/c0t8d0:AUTO -

8. Make the disks able to boot without quorum
mkboot -a "hpux -lq" /dev/rdsk/c0t5d0
mkboot -a "hpux -lq" /dev/rdsk/c0t8d0

9. Make sure both are set up as the primary and backup boot devices
setboot
if you need to change enter
setboot -a 8/0.8.0

Re: Mirror root disk

Thierry Poels_1 — Fri, 30 Mar 2001 18:26:27 GMT

Mark thanks for the extended version :)
(copied & pasted for future reference)

but a little remark at point 5. :
you should define where the mirror copy should reside : suppose a VG00 with 10 disks, the mirror copies of the first 3 lvols could be placed on another disk instead of your second boot disk!

regards,
Thierry.

Re: Mirror root disk

Vincenzo Restuccia — Fri, 30 Mar 2001 18:31:32 GMT

# pvcreate -B /dev/rdsk/cxtyd0 mkboot /dev/rdsk/cxtyd0
# mkboot -a "hp-ux -lq(;0)/stand/vmunix" /dev/rdsk/cxtyd0
mkboot -a "hp-ux -lq(;0)/stand/vmunix" /dev/rdsk/cwtzd0 (primary disk)

Step 2 (add the disk to VG00)
# vgextend /dev/vg00 /dev/dsk/cxtyd0

Step 3 (mirror the required lvols to this disk)
# lvextend -m 1 /dev/vg00/lvolx /dev/dsk/cxtyd0
Step 4
lvlnboot -Rv

step 5

setboot -a hardware path (es. 0/0/0/x/0.y) (for alternate boot)

Re: Mirror root disk

Mark Mitchell — Fri, 30 Mar 2001 18:54:10 GMT

Good point....

Re: Mirror root disk

Bill Hassell — Sat, 31 Mar 2001 01:37:04 GMT

When you add the additional disk in mirror order to the volume group, the default behavior is to start the mirror extents on the first disk. However, it is a good idea to use lvextend -m 1 with the volume group AND the physical disk device file to force the mirroring to the right disk.

NOTE: The first 3 lvols (/stand, swap and /) must start at the begining of the mirror disk. If not, the mirror will start to boot and then fail as the next two volumes are not contiguous.

Re: Mirror root disk

Giuseppe Giardina — Mon, 02 Apr 2001 11:49:32 GMT

Hi:
I'm sorry, but there is no easy way to make a mirror disk for HP-UX.
First of all, you must buy the HP-UX Mirror disk software: if you haven't this software, forgot about thinkink to make a mirror disk of any kind. Second, when you have the sofware, do NOT use SAM to make a funcional root disk (does not work for me), but read the manual and follow the steps about the command about vgcreate, vgextend, vg*, etc (it work for me).
Bye,
Giuseppe Giardina.