I'm teaching our storage team to use the System Manager to resize volumes (both source and destination snap mirror volumes)

Then one team member noticed this old issue - when the SM src/dest pair volumes are shrunk - the new size is not reflected on the destination - even after a SM update. 

Last year I wrote about this http://www.vmadmin.info/2011/04/shrinking-snapmirror-destination.html

and the solution at the time was to break the SM to have the destination space reclaimed.

But is there a better method?

This script shows I have volumes with space reclaimable:

ssh na01 -l root vol status -b | awk '{print $0" diff = "($3-$4)*4096/1024/1024" gb"}'
Volume              Block Size (bytes)  Vol Size (blocks)   FS Size (blocks)    
------              ------------------  ------------------  ----------------    
vol0           4096                78643200            78643200            diff = 0 gb
pweb           4096                249036800           249036800           diff = 0 gb
vm64           4096                810675078           805306368           diff = 20971.5 gb
eweb2          4096                13369344            13107200            diff = 1024 gb
sbackup2       4096                311951361           308543488           diff = 13312 gb
vds            4096                191365120           180879360           diff = 40960 gb
svm2           4096                563714458           563714458           diff = 0 gb
sarchive       4096                562141594           549034394           diff = 51200 gb
svm4           4096                629145600           603979776           diff = 98304 gb
vb2            4096                2883584             2685440             diff = 774 gb
cldb           4096                1184890880          1184104448          diff = 3072 gb
cl2            4096                1848377344          939524096           diff = 3550208 gb

thanks