Re: SVM: tearing down and putting back a RAID 5 on the same system?

Hi,

I think the following may work....

( I have reinitialised a RAID 5 volume configuration once, without
loosing any data)

I would:

1. Run a metastat -p and save the output.
2. Remove any metadb's on the 3 disks. Make sure you have metadb's on
root disks.
3. Bring the system down with init 5.
4. Label the 3 disks with slot position.
5. Unplug the 3 disks.
6. Bring system up.
7. Remove the RAID5 volume (metaclear -r d<RAID5>)
8. Partition the new disks.
9. Create new metadb's and a new mirrored volume.


IF you need to restore the RAID5 volume.

1. Remove metadb's on new mirrored volume.
2. Bring system down.
3. Reinsert the 3 RAID5 disks.
4. Bring system up.
5. Run metainit with the -r -k switches and the 3 disks in EXACT same
order.
e.g. metainit d<RAID5> -r disk1 disk2 disk3 -k
DO NOT FORGET -k OPTION!!!
6. Re-add the metadb's.

That should hopefully work...

Regards,
Daniel


Dan Stromberg wrote:
Hi folks.

I have a mail server that currently has its mail spool on 3 disks in a
RAID 5 with one hot spare.

We need to replace it with 2 larger disks in a mirror - not a root mirror,
just a plain old mirror. It probably goes without saying that I want to
minimize downtime on this server.

To do this, I've been planning to tear down the RAID 5, remove those
disks, and set up a mirror in the now-unoccupied drive bays. The
tearing-down commands I had in mind are:

metadb -f -d /dev/dsk/c0t8d0s7
metadb -f -d /dev/dsk/c0t10d0s7
metadb -f -d /dev/dsk/c0t12d0s7
metaclear -f hsp001
metaclear -f /dev/md/dsk/d6

...or perhaps just:

metaclear -f -r /dev/md/dsk/d6

My question is this: If for some reason the new root mirror doesn't work
out, is there a way to set the unchanged four disks in the RAID 5 back up
again, without losing the data that is on them? And are they truly
"unchanged" if I run the commands above? "metaimport -r" seems to
think they aren't importable on my test system, after running the
metaclear -r above.

Can disksets do this (tear down and put back without data loss)? And if
so, is this a Solaris 10-only feature? I'm doing this on Solaris 8 10/01.

Thanks!

.

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