Thanks to all who responded so quickly. Consensus seems
to be that plan will generally work, but vdump/vrestore to new
OS disks while system is up will give me a better copy and prevent
possible problems with restoring from a backup that didn't know
about new LSM config.
Other items were:
* may not need to take system down if disks are hot-pluggable
* /etc/passwd, /var/tcb, /var/... files might change
during vdump/vrestore
* "consvar" could be used to change console params - I've crashed
a system or two, though, using consvar, so am wary!
* if a cluster, could be very complicated, may need to remove
a cluster member and re-add to recreate its boot disk.
* make sure to modify /etc/rc.config swap partition reference.
* V5.* makes the whole exercise much more complicated!
John Losey had an interesting scenario where you keep the OS disks at same
locations by swapping old with new and then booting CD and using
vdump/vrestore,
here are details:
--------------------------------------------------------
One thought might be to: (Assuming 4.0x, I'm not overly sure how 5.x would
handle something similar)
* Take the system down.
* Move the two old disks to the empty slots.
* Put the new disks into the newly available slots. (this would keep LSM &
/etc/fstab happier).
* Boot to the OS CD, go to shell mode.
* Partition new disks.
* Mount new disk & old disk (only need to mount the primaries, since you
implied they are LSM mirrors).
* Use vdump | vrestore (syntax near the bottom of the manpage for vrestore)
to dump from old OS disk to new OS disk.
* Shutdown the system.
* Boot to the new disk (which should be the same console setting as it was
before)
Since LSM is expecting your / & /usr part of the LSM Mirror to be at a
specific disk (say /dev/rz0), by putting the new disks at that location,
you'll keep LSM happy while still migrating to new disks. If you're
using Tru64 5.x, things get a bit different because the old disks
would probably still be /dev/disk/dsk0 (I believe it tracks the serial#
of the drive and would notice that the old drives were at a new Target
and keep the old name). Though there have been posts lately talking
about how to clear out the device information, so this might be able
to be worked around as well.
-------------------------------------------------------------
alan_at_nabeth notes that in V4 moving the physical system disk is easy,
but in V5 OS remembers what disk it was on and makes things more complicated.
He also notes that there should be summaries about the v5 issue
of modifying the hardware database, and that there might be a best
practices paper on Compaq's website.
--------------------------------------------------------------
Several people sent more or less detailed instructions, you know who
you are, huge thanks to you!!!!!!!
Regards,
Judith Reed
Received on Wed Mar 27 2002 - 13:38:39 NZST