Usage: sg_sync    [--16] [--count=COUNT] [--group=GN] [--help] [--immed]
                  [--lba=LBA] [--sync-nv] [--timeout=SECS] [--verbose]
                  [--version] DEVICE
  where:
    --16|-S             calls SYNCHRONIZE CACHE(16) (def: is 10 byte
                        variant)
    --count=COUNT|-c COUNT    number of blocks to sync (def: 0 which
                              implies rest of device)
    --group=GN|-g GN    set group number field to GN (def: 0)
    --help|-h           print out usage message
    --immed|-i          command returns immediately when set else wait
                        for 'sync' to complete
    --lba=LBA|-l LBA    logical block address to start sync operation
                        from (def: 0)
    --sync-nv|-s        synchronize to non-volatile storage (if distinct
                        from medium). Obsolete in sbc3r35d.
    --timeout=SECS|-t SECS    command timeout in seconds, only active
                              if '--16' given (def: 60 seconds)
    --verbose|-v        increase verbosity
    --version|-V        print version string and exit

Performs a SCSI SYNCHRONIZE CACHE(10 or 16) command