vg00 and and mkboot

[Juan M Leon]

Hello all, I wanted to confirm with you guys about the following.
I have a server with 2 disks and 2 mirrors as part of my vg00.
The first disk has the normal lvol1 to lvol10 filesystems and the second disk has additional lvol for applications as part of vg00.
now based on the output below does the second disk with its mirror need to be bootable or not necesary. If not will that prevent the server from boot in case of any failure.

#-> lvlnboot -v
Boot Definitions for Volume Group /dev/vg00:
Physical Volumes belonging in Root Volume Group:
/dev/dsk/c0t0d0 (0/0/1/1/0.0.0) -- Boot Disk
/dev/dsk/c2t0d0 (2/0/1/1/0.0.0) -- Boot Disk
/dev/dsk/c0t2d0 (0/0/1/1/0.2.0) Does it need to be bootable?
/dev/dsk/c2t2d0 (2/0/1/1/0.2.0) -- Boot Disk is it needed as bootbale?
Boot: lvol1 on: /dev/dsk/c0t0d0
/dev/dsk/c2t0d0
Root: lvol3 on: /dev/dsk/c0t0d0
/dev/dsk/c2t0d0
Swap: lvol2 on: /dev/dsk/c0t0d0
/dev/dsk/c2t0d0
Dump: lvol2 on: /dev/dsk/c0t0d0, 0

The disk c0t2d0 and it's mirror c2t2do have the following filesystems
--- Distribution of physical volume ---
LV Name LE of LV PE for LV
/dev/vg00/u01 1606 1606
/dev/vg00/adm 128 128

I think does not need to be bootable as lvol1,lvol2 and lvol3 resides on the other disk, but I might be wrong thats why I wanted your input on this.

All suggestions are appreciated.

Thank you

Juan

[Patrick Wallek · Accepted solution]

No c0t2d0 and c2t2d0 do NOT have to be bootable.

You configuration looks fine!

[Torsten.]

Your config is good.

Only the disks that have lvol1 to 3 on it must be bootable.

The system will do the following:

- firmware boots the first configured disk and load the system loader from it
- the system loader will get the first 3 LVOLs and is going to load the kernel

until now it doesn't matter if you have more than 1 disk in you VG, all others come into play later.

[James R. Ferguson]

Hi Juan:

FIrst, placing non-standard vg00 logical volumes on your boot (vg00) disk makes operating system upgrades, and cloning of vg00 by whatever means, more difficult. In my opinion, rid your vg00 of application logical volumes. Disk is (relatively cheap!

That said, for a mirror disk to be bootable, the first three (lvol1, lvol2 and lvol3) logical volumes _must_ be mirrored in that order. The physical volume that constitutes the boot disk must have been created with the '-B' option of 'pvcreate' and a 'mkboot' performed thereon. The details can be found here (in Appendix-D):

http://docs.hp.com/en/5991-1236/When_Good_Disks_Go_Bad_WP.pdf

You should also set the "low quorum" for _BOTH_ disks:

# mkboot -a "hpux -lq" /dev/rdsk/cXtYdZ

Now, having said this, you want high-availablity in the event of a disk failure. Thus you want to mirror *every* logical volume on your boot disk. Afterall, you want a fully functional system (or at least the data thereof) anytime you have a failure. Booting following a disk hardware failure is just one aspect.

Regards!

...JRF...

[Mark S Meadows]

Hi Juan,

Disks c0t0d0 and c2t0d0 are the only required boots disk, with c2t0d0 being the mirror of c0t0d0.

I would also check the output of the "setboot" command to ensure that your primary and alternate boot paths are configured to point to their respective boot disk.

man setboot for further information if required.

The only other thing that I would also point out is that vg00 is normally specifically for operating system file systems and that application specific file systems are usually configured within separate vg's like vg01, vg02 etc......., but this can differ from site to site depending upon in house standards.

Regards,

Mark

[Juan M Leon]

All thanks for your input on this question, I wanted to be sure that is the right thing to not put the second disk as bootable.
As per the comment on app lvols on vg00 I agree, however it was build before my time and on this complex envirnment I rather not make changes unless it is necesary.


thank you again

Juan