topic Re: Problem creating a bootable tape with LSM mirrored drives in Operating System - Tru64 Unix

Problem creating a bootable tape with LSM mirrored drives

Howard Anderson_2 — Wed, 25 Jan 2006 06:31:13 GMT

I am trying to create a bootable tape to provide a disaster recovery backup of my system disk.
However I am using LSM to mirror the system disk, and when I try to create the bootable tape it claims mirrored disks are not supported.
Is there a way around this? Or a different approach?

(I am using ADvFS, and I have created a vdump of all partitions on the system disk, but methinks this won't help if both mirrors are rendered u/s. Unlikley but possible.)

Tru64 5.1B (patch kit 5) on DS25 Alphaserver
DDS 72 Dat drive.
2 x 36.4 GB Ultra SCSI 3 drives in the DS25.

I am using 'sysman boot_tape' with default options as a first try. (I will talior it later.)

Many thanks,

Howard Anderson.

Re: Problem creating a bootable tape with LSM mirrored drives

Johan Brusche — Wed, 25 Jan 2006 13:06:08 GMT

Howard,

As you found out btcreate cannot save an LSM based boot-disk. See also manpage btcreate.

The only approach left is as you did, keep vdump of root usr and var, but also keep a printout of the disk's disklabel an run volsave for all diskgroups.

Then boot from CD.
Use the printout of the disklabel to recreate the same (bootable)on the (new/garbled) disk.
vrestore root_domain, usr_domain and var_domain.

Mount the restored root on /mnt
cd /mnt/etc/vol
rm -r *
cd /mnt/etc
with editor comment out 3 LSM lines in inittab and point swapdevice to partition b of disk, not the LSM-volume.

Now boot from restored disk.
run volinstall and volsetup
re-encapsulate root,usr and var : volencap -a
then reboot
then volrootmir to recreate mirror plexes.
finally define remaining disk in other diskgroups and import these diskgroups.
If the import does not succeed a volrestore based on earlier volsave will help.

Rgds,
___ Johan./

Re: Problem creating a bootable tape with LSM mirrored drives

Ivan Ferreira — Wed, 25 Jan 2006 13:58:48 GMT

There are some odds, for example, in the LSM doc you have:

To facilitate recovery of environments that use LSM, you can use the bootable tape utility. This utility enables you to build a bootable standalone system kernel on magnetic tape. The bootable tape preserves your local configuration and provides a basic set of the LSM commands you will use during restoration.

But there is not extra information. I have verified the advfs administration manual also but in either one there is a procedure to recover the root domain with LSM.

It's very likely that the Johan's procedure will work.

Re: Problem creating a bootable tape with LSM mirrored drives

Howard Anderson_2 — Mon, 03 Apr 2006 09:33:56 GMT

I haven't tried all of Johans solution, (just the saving element), but I concurr with Ivan that this should work.
Many thanks for your help.