When initially instantiating and setting up accounts on ZFS filesystem (in my case, under OpenSolaris 2009.06), it is beneficial to store user data on a pool other than root pool (i.e., rpool). This is because rpool cannot be composed from multiple hard disks and thus cannot be changed in size (unless it is mirrored) [ref].
So, start by adding a disk to the machine and creating a pool from it.
The following commands lists names of disks available in the system:
afgane@opensolaris:~$ pfexec format
Searching for disks...done
AVAILABLE DISK SELECTIONS:
0. c7d0
/pci@0,0/pci-ide@1,1/ide@0/cmdk@0,0
1. c7d1
/pci@0,0/pci-ide@1,1/ide@0/cmdk@1,0
2. c8d1
/pci@0,0/pci-ide@1,1/ide@1/cmdk@1,0
Specify disk (enter its number): ^C
afgane@opensolaris:~$
From this, we see that the above system has three disks: c7d0, c7d1 and c8d1
NOTE: Instead of creating a filesystem on a physical disk, you may create it from a simple file that exists in current file system. To do this, create a file on the system of desired size and use it instead of the disk name. Use the following command:
afgane@opensolaris:~$ dd if=/dev/zero of=myfile bs=1024 count=10
This command creates a file called "myfile" filled with zeros with a block size of 1000 multiplied 10 tens or 10K (i.e., created file of size 10K bytes).Before seeing which of the disks is being used by which pool, we need to see what pools are available on the machine. Do so by issuing the following command:
root@opensolaris:~# zpool list
NAME SIZE USED AVAIL CAP HEALTH ALTROOT
rpool 34.8G 3.79G 31.0G 10% ONLINE -
root@opensolaris:~#
From this output we can see that there is only one pool available on the machine, namely rpool.
Next, in order to see which disk is being used by rpool, issue the following command:
afgane@opensolaris:~$ zpool status
pool: rpool
state: ONLINE
scrub: none requested
config:
NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
c7d0s0 ONLINE 0 0 0
errors: No known data errors
afgane@opensolaris:~$
This tells us that disk named c7d0s0 is used by rpool.
We can now create a new pool and add one of the two extra disks that are available in the machine to this newly created pool. Do so by executing following command (note that you must be root to issue this command):
root@opensolaris:~$ zpool create myPool c7d1
We can now see our newly created pool and can access it as a regular directory on the machine:
root@opensolaris:~# zpool list
NAME SIZE USED AVAIL CAP HEALTH ALTROOT
myPool 1.95G 32.7M 1.92G 1% ONLINE -
rpool 34.8G 3.79G 31.0G 10% ONLINE -
root@opensolaris:~#
root@opensolaris:~# cd /myPool
If you ever add another disk to this machine, it is very simple to add it to the overall pool of available space. We will use the third disk that is available in this machine, as follows (remember that you need to be root to issue this command):
root@opensolaris:~# zpool add myPool c8d1
And here is the list of the new pool arrangement, showing the increased pool size:
root@opensolaris:~# zpool list
NAME SIZE USED AVAIL CAP HEALTH ALTROOT
myPool 2.95G 32.7M 2.91G 1% ONLINE -
rpool 34.8G 3.79G 31.0G 10% ONLINE -
root@opensolaris:~#
