Changing from single to mirrored boot disks

[Phil Squire]

Hello all

I have just installed 2 similar internal disks on my k-class server with the intention of making them mirrored boot disks, and ultimately re-allocating the existing root disk as a standard volume.

Can someone outline the basic steps for doing this please and point out any pitfalls.

The new disks are not the same type as the existing root disk. They are larger. There is only one physical disk in vg00 presently.

Thanks in advance.
Phil

[Thierry Poels_1]

Hi,

FYI mirrored disks do not have to be identical.

To create a mirrored boot disk:

pvcreate ???B /dev/rdsk/c2t8d0 (-f = force)

mkboot /dev/rdsk/c2t8d0

mkboot ???a ???hpux ???lq(;0)/stand/vmunix??? /dev/rdsk/c2t8d0
mkboot ???b /usr/sbin/diag/lif/updatediaglif ???p HPUX ???p ISL ???p AUTO ???p LABEL /dev/rdsk/c2t8d0

vgextend /dev/vg00 /dev/dsk/c2t8d0

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
???
(first three lvols in sequence!)

good luck,
Thierry.

[Victor BERRIDGE]

Hi,
pvcreate -B /dev/rdsk/cXd0s2
#mkboot -l /dev/rdsk/cXd0s2
#mkboot -a "hpux (;0)/stand/vmunix" /dev/rdsk/cXd0s2
then
#vgextend /dev/vg00 /dev/dsk/cXd0s2
then mirror all your lv in rootvg
#lvextend -m 1 /dev/vg00/lvol1 /dev/dsk/cXd0s2
#lvextend -m 1 /dev/vg00/lvol2 /dev/dsk/cXd0s2
etc...
Finally
#lvlnboot -r /dev/vg00/lvol1
#lvlnboot -s /dev/vg00/lvol2
#vgcfgbackup vg00



ALl the best

Victor

[Victor BERRIDGE]

Hi again??
I remebered there is a doc:
Document ID: rcfaxlvm001


All the best

Victor

[melvyn burnard]

You could of course visit the online docs web:
http://docs.hp.com/hpux/onlinedocs/B2355-90742/B2355-90742.html
and read through the managing disks and file systems section.

[Marcin Wicinski]

Hi,
If you have installed OnLine Diagnostics, you should update LIF area on mirror disk (after all operations described in previous replies):

# lifls /dev/rdsk/
# lifls /dev/rdsk/
compare two outputs
# mkboot -b /usr/sbin/diag/lif/updatediaglif2 -p -... /dev/rdsk/

updatediaglif2 - for L,N,V-class,SD (PCI bus)
updatediaglif - other

# lifls /dev/rdsk/
# lifls /dev/rdsk/
compare two outputs

[Roger Baptiste]

hi,

You can take a ignite tape of the existing root/boot disk and reinstall it on one of
the new disks.

eg: /opt/ignite/bin/make_tape_recovery -i

this will guide you take the ignited bootable tape of the existing root disk.

Then, reboot the system and boot from the
tape, install its contents on one of the
new disks. Once you are done, mirror
the other disk with the boot disk.

HTH
raj

[James R. Ferguson]

Hi Phil:

I have several comments.

First, remember you need to license MirrorDisk/UX to mirror in the first place.

Second, the value of mirrored disks, particularly for the boot disk, is high-availability. You indicate that your primary goal is really disk replication.

Third, if your new disk is larger, then you probably want to begin with a 'vgcreate' to establish appropriate 'max_pe', and pe_size' values for the *physical* capacity. See the man pages (1M) for 'vgcreate' for more details. By mirroring your new disk with your existing, smaller disk, you may deprive yourself of the full use of the new, larger disk's extents! The use of Ignite to reconstruct your vg00 in cases like this is absolutely ideal.

Last, I whole-heartedly second Melvyn's suggestion to read the section on mirroring in the administration guide. These manuals are very well written and are a tremendous resource.

Regards!

...JRF...

[Phil Squire]

Thanks everybody for your comments and suggestions. Yes I agree about the on-line documentation, it is an essential resource and I do use it as a primary source of reference.

However, I put this sort of work into the 'scary' category and experience has taught me that there is no substitute for the advice of people who have already been through it.

Regards
Phil

[Krishna Prasad]

I am not sure if I read your question correctly or not. It sounded like you installed two new drives that you want to be mirrors of your root disk. Then free up the orginal root/boot disk after being mirrored to the new disks.

If I read this correctly others have given you several examples to use lvm to establishing your mirrors that will work fine.

But don't forget to change your primary boot disk address if you change your original boot disk to a new disk.

[Craig Rants]

Phil,
Pay particular attention to the posts with the updatediaglif command in them. That it a little know part of mirroring vg00 and it shows the high level of detail your receieved in your response.

Don't worry about trying this out, you'll be fine.

Good Luck,
C

[Phil Squire]

Thanks for the advice. What I actually want to do is make an entirely new primary boot disk and mirror the other new disk to it, ultimately removing or relocating the original boot disk.

Regards
Phil