Solaris How to grow soft partition

(root)# metastat d31
d31: Soft Partition
Device: d20
State: Okay
Size: 8388608 blocks (4.0 GB)
Extent Start Block Block count
0 2097154 2097152
1 13262854 2097152
2 18071563 4194304

Device Relocation Information:
Device Reloc Device ID
c0t0d0 Yes id1,sd@SSEAGATE_ST336607LSUN36G_3JAX268Y000075139UX8
c0t1d0 Yes id1,sd@w4849544143484920444b3332454a2d33364e4320202020203433353139343634
(root)# metastat d20
d20: Mirror
Submirror 0: d21
State: Okay
Submirror 1: d22
State: Okay
Pass: 1
Read option: roundrobin (default)
Write option: parallel (default)
Size: 45929322 blocks (21 GB)

d21: Submirror of d20
State: Okay
Size: 45929322 blocks (21 GB)
Stripe 0:
Device Start Block Dbase State Reloc Hot Spare
c0t0d0s3 0 No Okay Yes


d22: Submirror of d20
State: Okay
Size: 45929322 blocks (21 GB)
Stripe 0:
Device Start Block Dbase State Reloc Hot Spare
c0t1d0s3 0 No Okay Yes


Device Relocation Information:
Device Reloc Device ID
c0t0d0 Yes id1,sd@SSEAGATE_ST336607LSUN36G_3JAX268Y000075139UX8
c0t1d0 Yes id1,sd@w4849544143484920444b3332454a2d33364e4320202020203433353139343634
(root)#
(root)# metattach d31 750M
d31: Soft Partition has been grown
(root)# growfs -M /export/home /dev/md/rdsk/d31
Warning: 1996 sector(s) in last cylinder unallocated
/dev/md/rdsk/d31: 9924608 sectors in 3436 cylinders of 27 tracks, 107 sectors
4846.0MB in 215 cyl groups (16 c/g, 22.57MB/g, 10816 i/g)
super-block backups (for fsck -F ufs -o b=#) at:
32, 46368, 92704, 139040, 185376, 231712, 278048, 324384, 370720, 417056,
9477408, 9523744, 9570080, 9616416, 9662752, 9709088, 9755424, 9801760,
9848096, 9894432,
(root)# df -k /export/home
Filesystem kbytes used avail capacity Mounted on
/dev/md/dsk/d31 4668164 3408354 1023092 77% /export/home
(root)# df -k /home/fpr/dat/in
Filesystem kbytes used avail capacity Mounted on
/dev/md/dsk/d31 4668164 3408355 1023091 77% /export/home
(root)#