VxVM relayout requires the additional space on old disks as the temporary area,
if there is no available spaces remained,how can we do ?

So I take some testing for above situation.I want to relayout a striped volume
vol3 within datadg from 3 columns to 4 columns:

# vxprint -g datadg -ht
v  vol3         -            ENABLED  ACTIVE   104857600 SELECT   vol3-01  fsgen
pl vol3-01      vol3         ENABLED  ACTIVE   104857728 STRIPE   3/128    RW
sd c1t10d0-03   vol3-01      c1t10d0  104857728 34952576 0/0      c1t10d0  ENA
sd c1t11d0-03   vol3-01      c1t11d0  104857728 34952576 1/0      c1t11d0  ENA
sd c1t12d0-03   vol3-01      c1t12d0  104857728 34952576 2/0      c1t12d0  ENA

And no space left on above three disks:
# vxdg -g datadg free
DISK         DEVICE       TAG          OFFSET    LENGTH    FLAGS
c1t10d0      c1t10d0s2    c1t10d0      143328768 192       -
c1t11d0      c1t11d0s2    c1t11d0      143328768 192       -
c1t12d0      c1t12d0s2    c1t12d0      143328768 192       -

So I add some physical disk into datadg,I intend to:
- use c1t13d0 as new column
- use c1t8d0 & c1t9d0 as temp. area

# vxdg -g datadg adddisk c1t8d0 c1t9d0 c1t13d0
# vxassist -g datadg relayout vol3 ncol=+1 wantalloc=c1t13d0 tmpsize=10g tmpalloc=c1t8d0,c1t9d0

Please note I use the keyword "tmpalloc" & "wantalloc",but after relayout,I noticed
the new column not assigned to c1t13d0 as I wanted:

# vxprint -g datadg -ht
v  vol3         -            ENABLED  ACTIVE   139810816 SELECT   vol3-01  fsgen
pl vol3-01      vol3         ENABLED  ACTIVE   139810816 STRIPE   4/128    RW
sd c1t10d0-06   vol3-01      c1t10d0  104857728 34952576 0/0      c1t10d0  ENA
sd c1t10d0-03   vol3-01      c1t10d0  143328768 128     0/34952576 c1t10d0 ENA
sd c1t11d0-06   vol3-01      c1t11d0  104857728 34952576 1/0      c1t11d0  ENA
sd c1t11d0-03   vol3-01      c1t11d0  143328768 128     1/34952576 c1t11d0 ENA
sd c1t12d0-06   vol3-01      c1t12d0  104857728 34952576 2/0      c1t12d0  ENA
sd c1t12d0-03   vol3-01      c1t12d0  143328768 128     2/34952576 c1t12d0 ENA
sd c1t8d0-03    vol3-01      c1t8d0   20971008 34952704 3/0       c1t8d0   ENA

As above,c1t8d0 is used originally for temp. area,but why the new data
was allocated on it ?seems the vxvm keyword "tmpalloc" & "wantalloc" not took
effect ?

Thanks.
Regards,
Simon