VxFS filesystems can be defragmented using the fsadm command. However,
the online reorganization and online resize features of fsadm are
enabled only with the HP OnLineJFS optional product.

Here are the relevant options:

  -D          Report on directory fragmentation.  If specified in
              conjunction with the -d option, the fragmentation
              report is produced both before and after the
              directory reorganization.

  -d          Reorganize directories.  Directory entries are
              reordered to place subdirectory entries first, then
              all other entries in decreasing order of time of last
              access.  The directory is also compacted to remove
              free space.

  -E          Report on extent fragmentation.  If specified in
              conjunction with the -e option, the fragmentation
              report is produced both before and after the extent
              reorganization.

  -e          Reorganize extents.  Minimize file system
              fragmentation.  Files are reorganized to have the
              minimum number of extents.

An example:

  # fsadm -dDeE /var

See fsadm_vxfs(1M) for further details.

No commands are available for defragmenting HFS filesystems.