Installing ZFS on an existing Solaris 10 install (UFS)

Hello, I am new to Solaris so i apologize upfront if my questions seem trivial.

I am trying to install a ZFS file system on a Solaris 10 machine with UFS already installed on it.

I want to run: # zpool create pool_zfs c0t0d0
then: # zfs create pool_zfs/fs

My question is more to do with the c0t0d0 disks.
When I run df, it shows /dev/dsk/c0t0d0s0 Mounted on /

Is this the disk i would use in the zpool create command?

If you already have installed Solaris on the c0t0d0s0 slice, then you will not be able to create a zpool on that disk, as its in use.
You should run the format command, and find a disk that is not mounted and run the zpool create command on it.

thanks, just run format with no arguments?

yes, just run it.
Then it will list your disks that Solaris can see.