in order to check space reclaim and unmap inside MSA then use command,
show disk-group-statistics
[disk-group disk-group]
[type linear|virtual]
There are few parameters in the output which give more details on this,
Pages Allocated per Min
Shown for a virtual disk group. The rate, in pages per minute, at which pages are allocated to volumes in the disk group because they need more space to store data.
Pages Deallocated per Min
Shown for a virtual disk group. The rate, in pages per minute, at which pages are deallocated from volumes in the disk group because they no longer need the space to store data.
Pages Reclaimed
Shown for a virtual disk group. The number of 4-MB pages that have been automatically reclaimed and deallocated because they are empty (they contain only zeroes for data).
Pages Unmapped per Minute
Shown for a virtual disk group. The number of 4-MB pages that host systems have unmapped per minute, through use of the SCSI UNMAP command, to free storage space as a result of deleting files or formatting volumes on the host.
More details customer can refer Command Line reference guide (page no 287),
http://h20564.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-c04957376
