A question on system disk copying that's slightly different than
the ones that have appeared here lately:
I want to make a copy of the system boot disk that can be booted and
used in an emergency. I'm using the method described here recently
(disklabel the target disk and use vdump to copy the partitions) on
some machines with straightforward root disks (e.g., all ufs or advfs)
and would like to do something similar in this case. But we've got
some production machines here that use LSM, which was setup before I
got here. The labels on these disks look like:
------------------------------------------------------------------------
# /dev/rrz0c:
type: SCSI
disk: rz28
label:
flags:
bytes/sector: 512
sectors/track: 99
tracks/cylinder: 16
sectors/cylinder: 1584
cylinders: 2595
sectors/unit: 4110480
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0 # milliseconds
track-to-track seek: 0 # milliseconds
drivedata: 0
8 partitions:
# size offset fstype [fsize bsize cpg]
a: 131472 0 4.2BSD 1024 8192 16 # (Cyl. 0 - 82)
b: 1051776 131472 unused 1024 8192 # (Cyl. 83 - 746)
c: 4110480 0 unused 1024 8192 # (Cyl. 0 - 2594)
d: 524271 131072 unused 1024 8192 # (Cyl. 82*- 413*)
e: 524271 131072 unused 1024 8192 # (Cyl. 82*- 413*)
f: 131472 1183248 4.2BSD 1024 8192 16 # (Cyl. 747 - 829)
g: 1840608 1314720 4.2BSD 1024 8192 16 # (Cyl. 830 - 1991)
h: 955152 3155328 LSMsimp # (Cyl. 1992 - 2594)
----------------------------------------------------------------------------
How can I copy the h partition, which contains the rootdg, and have the
new disk just boot up and mount the other LSM volumes and so on? Can I just
use dd to copy the partition to the new disk (say, rz1), edit the entry
in /etc/vol/volboot to point to rz1h, and then be able to simply
boot off the new disk and have everything work transparently?
Another option we've talked about is using LSM's mirroring capabilities
to make this copy of the boot/root disk. Has anyone done this,
successfully or otherwise? How well does it work? I confess that
the root encapsulation procedure makes me a little nervous - should it?
These machines are running Digital UNIX 3.2C, if that makes a difference.
Which brings up another question: I'm planning to upgrade to 4.0x; if
I pick the LSM-mirror option, should I upgrade before I encapsulate
the root partition, or after?
(For the record, I think that in an ideal world all I should have to do
would be type something like "mirror rz0 on rz1" and be done with it. :) )
Thanks in advance.
-Bill
Received on Tue Apr 15 1997 - 22:50:29 NZST