NAME

       hd-idle - spin down idle hard disks

SYNOPSIS

       hd-idle [options]

DESCRIPTION

       hd-idle  is  a  utility  program for spinning down external disks after a period of idle time. Since most
       external IDE disk enclosures don't support setting the IDE idle timer, a program like hd-idle is required
       to spin down idle disks automatically.

       A word of caution: hard disks don't like spinning up too often. Laptop disks  are  more  robust  in  this
       respect  than desktop disks but if you set your disks to spin down after a few seconds you may damage the
       disk over time due to the stress the spin-up causes on the spindle motor  and  bearings.  It  seems  that
       manufacturers recommend a minimum idle time of 3-5 minutes, the default in hd-idle is 10 minutes.

       One  more  word of caution: hd-idle will spin down any disk accessible via the SCSI layer (USB, IEEE1394,
       ...) but it will NOT work with real SCSI disks because they won't spin up automatically.  Thus  it's  not
       called scsi-idle and I don't recommend using it on a real SCSI system unless you have a kernel patch that
       automatically  starts the SCSI disks after receiving a sense buffer indicating the disk has been stopped.
       Without such a patch, real SCSI disks won't start again and you can as well pull the plug.

OPTIONS

       -a name
              Set device name of disks for subsequent idle-time parameters (-i).  This parameter is optional  in
              the  sense  that there's a default entry for all disks which are not named otherwise by using this
              parameter. This can also be a symlink (e.g. /dev/disk/by-uuid/...)

       -i idle_time
              Idle time in seconds for the currently named disk(s) (-a <name>) or for all disks.

       -l logfile
              Name of logfile (written only after a disk has spun up). Please note that this option might  cause
              the  disk  which  holds  the  logfile to spin up just because another disk had some activity. This
              option should not be used on systems with more than  one  disk  except  for  tuning  purposes.  On
              single-disk systems, this option should not cause any additional spinups.

       -t disk
              Spin-down the specfified disk immediately and exit.

       -d     Debug  mode.  This  will  prevent  hd-idle  from  becoming  a  daemon  and print debugging info to
              stdout/stderr

       -h     Print usage information.

DISK SELECTION

       The parameter -a can be used to set a filter on the disk's device name (omit /dev/) for subsequent  idle-
       time settings. The default is all disks:

       1)     A  -i  option before the first -a option will set the default idle time; hence, compatibility with
              previous releases of hd-idle is maintained.

       2)     In order to disable spin-down of disks per default,  and  then  re-enable  spin-down  on  selected
              disks, set the default idle time to 0.

EXAMPLE

       hd-idle -i 0 -a sda -i 300 -a sdb -i 1200

       This  example  sets the default idle time to 0 (meaning hd-idle will never try to spin down a disk), then
       sets explicit idle times for disks which have the string "sda" or "sdb" in their device name.

AUTHOR

       hd-idle was written by Chistian Mueller <chris@mumac.de>

       This manual page was written by Christian Mueller <chris@mumac.de>, for the Debian project  (and  may  be
       used by others).

                                               September 29, 2011                                     HD-IDLE(8)