Veritas File System (VxFS) supports reclamation of free storage on a Thin Storage LUN. Free storage is reclaimed using the fsadm command. You can perform the default reclamation or aggressive reclamation. If you used a file system for a long time and must perform reclamation on the file system, Symantec recommends that you run aggressive reclamation. Aggressive reclamation compacts the allocated blocks, which creates larger free blocks that can potentially be reclaimed.
See the fsadm_vxfs
(1M) manual page.
Thin Reclamation is only supported on file systems mounted on a VxVM volume.
Thin Reclamation is not supported for file systems mounted on RAID5 volumes.
Veritas File System also supports reclamation of a portion of the file system using the vxfs_ts_reclaim() API.
See the vxfs_ts_reclaim
(3) manual page and the Veritas File System Programmer's Reference Guide.