RAID1 volume maintenance

[John Courcoul]

So I was left with a SunFire V245 server that hosts several important
services with two internal 146GB HDDs in RAID1 mirror config, containing
the OS and applications and an external SAN with the data files. One of
the two internal HDDs has failed and I need to replace it with a spare I
have procured and is currently in an antistatic bag.

As per the manual, the way to go about the replacement will be:

1. Put the new HDD in the chassis and have the OS recognize it.
2. Partition the new HDD identical to the failed unit.
3. Add the slices on the new as submirrors.
4. Detach the submirrors of the failed HDD.
5. Unmount any non-mirrored slices on the failed HDD.
6. Remove the dead HDD and use as a doorstop, paperweight, etc.

Am I missing anything?

What's the command used to add the new HDD to the system without having
to do an INIT 6 and reboot the system?

Do I need to format the slices and create UFS filesystems on them before
attaching as submirrors, or do I just do the attach with METAREPLACE and
let it synch itself?

Thanks for any insights.

JMC

[Stefaan A Eeckels]

On Mon, 25 Jun 2012 07:49:53 -0500

Post by John Courcoul
So I was left with a SunFire V245 server that hosts several important
services with two internal 146GB HDDs in RAID1 mirror config,
containing the OS and applications and an external SAN with the data
files. One of the two internal HDDs has failed and I need to replace
it with a spare I have procured and is currently in an antistatic bag.
1. Put the new HDD in the chassis and have the OS recognize it.
2. Partition the new HDD identical to the failed unit.
3. Add the slices on the new as submirrors.
4. Detach the submirrors of the failed HDD.
5. Unmount any non-mirrored slices on the failed HDD.
6. Remove the dead HDD and use as a doorstop, paperweight, etc.

That's not quite how I would do it. This procedure creates a new set
of submirrors, which is rather complex, error-prone, and quite
unnecessary.

Post by John Courcoul
Am I missing anything?
What's the command used to add the new HDD to the system without
having to do an INIT 6 and reboot the system?

Here's how I replace a failed SVM-only disk:

First, remove the dead disk, and plug the new disk in the bay you've
removed the dead disk from. The V245 supports hot-swapping.

Then, use the following command to copy the vtoc from the active disk:

# prtvtoc -s /dev/rdsk/c5t1d0s2 | fmthard -s - /dev/rdsk/c5t2d0s2

(assuming that the running disk is c5t1d0s2 and the new, empty disk is
c5t2d0s2).

Finally, use metareplace to sync the slices:

# metareplace -e themirror c5t2d0s0

etc.

Post by John Courcoul
Do I need to format the slices and create UFS filesystems on them
before attaching as submirrors, or do I just do the attach with
METAREPLACE and let it synch itself?

No, fmthard takes care of partitioning, and metareplace only needs a
slice.

Take care,

[John Courcoul]

Post by Stefaan A Eeckels
On Mon, 25 Jun 2012 07:49:53 -0500

Post by John Courcoul
So I was left with a SunFire V245 server that hosts several important
services with two internal 146GB HDDs in RAID1 mirror config,
containing the OS and applications and an external SAN with the data
files. One of the two internal HDDs has failed and I need to replace
it with a spare I have procured and is currently in an antistatic bag.
1. Put the new HDD in the chassis and have the OS recognize it.
2. Partition the new HDD identical to the failed unit.
3. Add the slices on the new as submirrors.
4. Detach the submirrors of the failed HDD.
5. Unmount any non-mirrored slices on the failed HDD.
6. Remove the dead HDD and use as a doorstop, paperweight, etc.

That's not quite how I would do it. This procedure creates a new set
of submirrors, which is rather complex, error-prone, and quite
unnecessary.

Post by John Courcoul
Am I missing anything?
What's the command used to add the new HDD to the system without
having to do an INIT 6 and reboot the system?

First, remove the dead disk, and plug the new disk in the bay you've
removed the dead disk from. The V245 supports hot-swapping.
# prtvtoc -s /dev/rdsk/c5t1d0s2 | fmthard -s - /dev/rdsk/c5t2d0s2
(assuming that the running disk is c5t1d0s2 and the new, empty disk is
c5t2d0s2).
# metareplace -e themirror c5t2d0s0
etc.

Post by John Courcoul
Do I need to format the slices and create UFS filesystems on them
before attaching as submirrors, or do I just do the attach with
METAREPLACE and let it synch itself?

No, fmthard takes care of partitioning, and metareplace only needs a
slice.
Take care,
--
Stefaan

COOL! This really takes the pain out of the exercise. I knew slice 2 had
to be good for something quick.

Thanks!

JMC