UPDATED SUMMARY: How to replace half an LSM mirror that is in ADVFs

From: <jreed_at_appliedtheory.com>
Date: Mon, 07 May 2001 08:51:22 -0400

After my summary I rec'd several additional msgs, one of which
was very detailed and saved my skin in the operation! Thus,
updated summary.

Question was whether I could replace half an LSM mirror
that has ADVFS laid on top of it by using just LSM
commands and have the replacement be transparent to ADVFS.

Alan_at_nabeth said:
        It should be transparent to AdvFS.

Alan Davis said:
 The instructions for doing this recovery are in the appendix
to the LSM manual in the docset.

Dr. Tom Blinn said:
If LSM does what it's supposed to do, AdvFS will never know that
it got done. AdvFS has no knowledge that the LSM volumes are
mirrored.

Octave Orgeron said:
This should be transparent for you. When you replace
the disk, LSM will auto copy to it what is on the half
of the mirror. This is completely transparent to the
File System in use. LSM is really just veritas, and
the mirror stuff is really great. You should only
notice a little performance hit while the disks sync
up.

John J. Francini provided a detailed response, and I was
able to use it line for line - THANKS!:

You should be able to do this without even having to take the system down.
And yes, of course it can be done with AdvFS volumes -- AdvFS and LSM
work well together.

Here's the text from a Web page we use internally here in release
engineering for replacing a bad mirror disk on our own systems
(V4.0F, AdvFS filesystems).

Note that the example commands assume that volume 2 of the two-volume
root mirror is the one that died, rather than volume 1 as in your
case. Also note that there's no steps for removing the /var LSM
partition -- it's basically the same as the others with the names
changed appropriately. The disk device names will, naturally, be
different in your environment. Take the names in the commands below
as examples only.

We've done these sorts of replacements before, in full multi-user
mode, with no one being the wiser.

        Replacing a failed LSM Volume


               Identify all devices

                     voldisk list ....... output
                     volprint -ht ....... output
                     volprint -ht | grep -E 'DISABLED|FAIL'
                     volprint -ht | grep -i root
                     volprint -ht | grep -i swap


               Remove ROOT LSM Partion

                     volplex dis rootvol-02
                     voledit -fr rm rootvol-02
                     voldg rmdisk rz17a
                            ---- if that does not work look for rz17a label
                            ---- voldg rmdisk rz17a02
                     voldisk rm rz17a



               Remove Swap LSM Partion

                     volplex dis swapvol-02
                     voledit -fr rm swapvol-02
                     voldg rmdisk rz17b
                     voldisk rm rz17b



               Remove usr LSM Partion

                     volplex dis vol-rz16g-02
                     voledit -fr rm vol-rz16g-02
                     voldg rmdisk rz17g
                     voldisk rm rz17g



               Double check everything

                     volprint -ht
                     volprint -ht | grep 17
                     voldisk list

                     Add new drive into LSM plex

                            volrootmir -a rz17
                            volprint -ht | grep 17
                            voldisk list
Received on Mon May 07 2001 - 12:52:19 NZST

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