Replacing a root pool disk example

Question

Replacing a root pool disk has several use cases:
1. Replace a small disk with a larger disk
2. Replace a failed disk with a replacement disk
3. Outright move a rpool to a different disk because you want to
The easiest way is to attach the replacement disk to an existing root pool disk.
I like this approach better than an outright replacement with zpool replace because
you can ensure the new disk is bootable while both disks are still attached.
On an x86 system running S11.1, its even easier (if you reinstall not upgrade) because your
rpool disk contains an EFI label and you don't have to mess with any labeling.
On a SPARC system running S11.1 or a SPARC or x86 system running S11, you'll still need to
apply an SMI (VTOC) label and s0, if necessary.
See the example below.
Thanks, Cindy
1. Create a new BE just to identify that all rpool data is available on the replacement
disk:
# beadm list
BE Active Mountpoint Space Policy Created
s11u1_24b NR / 4.02G static 2012-12-05 10:24
# beadm create s11u1_backup
# beadm list
BE Active Mountpoint Space Policy Created
s11u1_24b NR / 4.02G static 2012-12-05 10:24
s11u1_backup - - 172.0K static 2012-12-11 08:46
2. Identify the existing root pool disk. You can see that this disk has an EFI label because
the device identifier is d0, not s0.
# zpool status rpool
pool: rpool
state: ONLINE
scan: none requested
config:
NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
c0t5000CCA012C8323Cd0 ONLINE 0 0 0
3. Attach the replacement disk.
# zpool attach rpool c0t5000CCA012C8323Cd0 c0t5000C500438124F3d0
Make sure to wait until resilver is done before rebooting.
You will see a message from FMA that the pool device is DEGRADED. This
is because the pool data is being resilvered onto the new disk.
4. Check the resilvering progress:
# zpool status
pool: rpool
state: DEGRADED
status: One or more devices is currently being resilvered. The pool will
continue to function in a degraded state.
action: Wait for the resilver to complete.
Run 'zpool status -v' to see device specific details.
scan: resilver in progress since Tue Dec 11 08:49:57 2012
42.6G scanned out of 71.7G at 132M/s, 0h3m to go
42.6G resilvered, 59.44% done
config:
NAME STATE READ WRITE CKSUM
rpool DEGRADED 0 0 0
mirror-0 DEGRADED 0 0 0
c0t5000CCA012C8323Cd0 ONLINE 0 0 0
c0t5000C500438124F3d0 DEGRADED 0 0 0 (resilvering)
5. When resilvering is complete, check that you can boot from the new disk.
You will need to boot the new disk specifically from either a SPARC boot PROM
or an x86 BIOS.
# zpool status
pool: rpool
state: ONLINE
scan: resilvered 71.7G in 0h8m with 0 errors on Tue Dec 11 08:58:45 2012
config:
NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
c0t5000CCA012C8323Cd0 ONLINE 0 0 0
c0t5000C500438124F3d0 ONLINE 0 0 0
6. If you can boot successfully from the new disk, detach the old disk.
# zpool detach rpool c0t5000CCA012C8323Cd0
Confirm your BE info is intact.
# beadm list
BE Active Mountpoint Space Policy Created
s11u1_24b NR / 4.03G static 2012-12-05 10:24
s11u1_backup - - 172.0K static 2012-12-11 08:46
7. If the new disk is larger than the existing disk, you will need to do one of the following
to see the expanded pool space.
# zpool set autoexpand=on rpool
# zpool online -e rpool c0t5000C500438124F3d0
8. Set the SPARC boot PROM or the x86 BIOS to boot from the new disk.

Answer 1

Where you're getting confused is that you do want to mirror, temporarily.
Make sure that s0 on the new disk covers the whole disk.
Then attach it the existing disk, as a mirror.
What for it to silver.
Then detach the old disk.
autoexpand is use when the existing disk is getting bigger. Thats not what you want to do.
You want to replace 1 disk with a second larger disk.