My S11 server has the following configuration:

disk #1 is used for rpool, which is the root pool I want to add disk #2 to increase the size available for the already mounted folders, but I can't add the disk to the existing rpool because its the root-pool.

Is there a way to make the new disk available for the "/" folder? Is my only option to create a new zpool and mount it under a new folder?



 root@raamee:~# zpool status
  pool: rpool
 state: ONLINE
 status: The pool is formatted using an older on-disk format. The pool can
         still be used, but some features are unavailable.
 action: Upgrade the pool using 'zpool upgrade'. Once this is done, the
         pool will no longer be accessible on older software versions.
  scan: none requested

         NAME        STATE     READ WRITE CKSUM
         rpool       ONLINE       0     0     0
           c4t0d0s0  ONLINE       0     0     0

root@raamee:~# zfs list
NAME                       USED  AVAIL  REFER  MOUNTPOINT
rpool                      130G  4.18G  4.59M  /rpool
rpool/ROOT                 101G  4.18G    31K  legacy
rpool/ROOT/S11-GA          152M  4.18G  7.33G  /
rpool/ROOT/S11-GA/var     17.4M  4.18G  5.20G  /var
rpool/VARSHARE             180K  4.18G   180K  /var/share
rpool/dump                8.25G  4.43G  8.00G  -
rpool/guests                31K  4.18G    31K  /guests
rpool/scratch             2.52M  4.18G  2.52M  /scratch
rpool/swap                20.6G  4.81G  20.0G  -

root@raamee:~# format
Searching for disks...done

       0. c4t0d0 <FUJITSU-MBB2147RCSUN146G-0505 cyl 17845 alt 2 hd 255 sec 63>
       1. c4t1d0 <FUJITSU-MBB2147RCSUN146G-0505-136.73GB>

3 Answers 3


Attach the second disk as a mirror of the first, wait for resilver, remove the first disk, set the properties to autoexpand. Don't forget to setup boot code or anything like that. Example:

zpool attach rpool olddisk newdisk
...wait, check using zpool status rpool
zpool detach rpool olddisk
zpool set autoexpand=on rpool

You cannot "expand" the rpool size by appending one disk to another (raid 0), as previously mentioned, however as Chris S mentioned below, you could attach a larger disk as a mirror, then, once the data is sync'd (resliver complete), detach the smaller disk. (oops now I see Chris's response too)

Here is a process to mirror the root disk... http://constantin.glez.de/blog/2011/03/how-set-zfs-root-pool-mirror-oracle-solaris-11-express

Follow that except that where they do:

prtvtoc /dev/rdsk/c7t0d0s0 | fmthard -s - /dev/rdsk/c7t1d0s0

... you will want to run format and make the size of slice 0 larger, probably the whole disk

# format /dev/rdsk/c4t1d0s0

(I will not go into great detail on the interactive format command)

# zpool attach rpool c4t0d0s0 c4t1d0s0

# zpool status rpool

WAIT UNTIL IT SAYS "resilver completed" (keep checking zpool status rpool)


Then detach the smaller rpool mirror and reboot, make sure you can boot again.

# zpool detach rpool c4t0d0s0


REFERENCE: http://docs.oracle.com/cd/E19963-01/html/821-1448/gjtuk.html#gjtui

Previous Answer:

After creating the pool using the command he specified:

zpool create mypool c4t1d0

Create a filesystem, for example:

zfs create mypool/home

... copy the data to the new disk ... (re)move the data from rpool disk, then set the mountpoint to a proper location, such as:

zfs set mountpoint=/export/home mypool/home

That is, of course, assuming that /export/home is where all the space is being used. You may have to do this in "single user" mode, or create a user with a home directory that is not in /export/home to complete this.

On a side note, your zfs list output looks funky, like it is missing something. rpool/ROOT is showing 101GB used, but the filesystems under it are only showing about 12.5GB REF, and far less USED. Do you by chance have other boot environments under rpool/ROOT that you "trimmed out" of your zfs list output? could you maybe destroy those bootenv's or at least the zfs filesystems to regain the space used in rpool/ROOT?


  • Sorry to be pedantic, but you can create a mirror of the rpool with a larger disk, then remove the smaller disk, and grow the rpool - this effectively increases the size of the rpool, which your first sentence says is not possible.
    – Chris S
    Feb 7, 2013 at 3:19
  • Chris S: You are correct, I hadn't thought of that. You should post the "correct" answer ;) Feb 8, 2013 at 20:42

Yes, I believe your only option is to create a new pool using the second disk. The only thing you can do with the rpool is mirror the disk - which won't make more space available. The rpool doesn't support striping, due to the difficulties it would pose with booting.

zpool create mypool c4t1d0

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