Having an alternate boot disk that is not a mirror

[Cindy Yoho]

I have mirrored my system disk, and now I would like to split the two and still be able to boot off of either one. Is this possible? I am going to boot off an ignite tape and resize the vg00 lvols on the primary, and if the ignite tape does not load I want to be able to boot off the other disk and get back to square one.

[Steven E. Protter]

Shalom,

Possible? Yes. With great difficulty.

Smart? No.

To safely boot the machine have the alternate boot disk on a single disk or your system may not boot.

SEP

[Matti_Kurkela]

... or with not-so-great-difficulty, if you can install & use the "Dynamic Root Disk" tool created by HP.

It's available for free from software.hp.com:
http://h20392.www2.hp.com/portal/swdepot/displayProductInfo.do?productNumber=DynRootDisk

HP-UX 11i v2 and above only. Follow the links on the product page for documentation.

You may find it easier to manually split the mirror and then re-clone using "drd clone", as DRD will have to do some clever LVM manipulations to make the other half appear as valid, bootable vg00 even though it is a separate entity from the active vg00.

MK

[Cindy Yoho]

I do have 2 separate disks, Steven I'm not sure what you mean by have the Alternate boot disk on a single disk. I am attempting to do this remotely, so I can't pull the disk out of the enclosure, which is what HP suggested. Matti, I am still on 11i v1, so DRD won't work for me :-(. I am investigating lvsplit - anyone have any experience using that?

[psreedhar]

Hi,
Use the following steps to acheive your recovery.

Assume your current boot disk is disk1,
and you want to mirror this on disk2 :)

1) Initialize the disk and make it bootable
pvcreate -B disk2 (use raw DSF)
2) Add the physical volume to the volume group
vgextend /dev/vg00 disk2

3) Use mkboot to place the boot utilities in the boot area and add the AUTO file.
mkboot disk2
mkboot -a "hpux -lq" disk2

4) Mirror all the Logical volumes in vg00
lvextend -m 1 /dev/vg00/lvol1 /dev/dsk/c1t6d0
lvextend -m 1 /dev/vg00/lvol2 /dev/dsk/c1t6d0
lvextend -m 1 /dev/vg00/lvol3 /dev/dsk/c1t6d0

and so on for all LVs in vg00.

5) Then boot from your ignite image restore that to disk1, if some thing goes wrong boot from disk2