ZFS auto expand mirror

[Ben Stuyts]

Hi,

I want to expand an existing mirror by replacing the existing drives with bigger ones. This is on:
FreeBSD xxx 7.3-STABLE FreeBSD 7.3-STABLE #2: Mon Sep 20 18:36:08 CEST 2010     root at xxx:/usr/obj/usr/src/sys/xxx  amd64

# zpool status home
  pool: home
 state: ONLINE
 scrub: scrub completed after 2h0m with 0 errors on Mon Sep 19 18:25:45 2011
config:

	NAME        STATE     READ WRITE CKSUM
	home        ONLINE       0     0     0
	  mirror    ONLINE       0     0     0
	    ad5s1a  ONLINE       0     0     0
	    ad7s1a  ONLINE       0     0     0

Will this version of FreeBSD auto-expand to the new, bigger drive size once they are both replaced? I did not see the autoexpand property in this pool. zpool is v13, zfs is v3.

Kind regards,
Ben