1HD-IDLE(1)                  General Commands Manual                 HD-IDLE(1)
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NAME

6       hd-idle - spin down idle hard disks
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SYNOPSIS

9       hd-idle [options]
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DESCRIPTION

12       hd-idle  is  a utility program for spinning down external disks after a
13       period of idle time. Since most external IDE disk enclosures don't sup‐
14       port  setting the IDE idle timer, a program like hd-idle is required to
15       spin down idle disks automatically.
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17       A word of caution: hard disks don't like spinning up too often.  Laptop
18       disks are more robust in this respect than desktop disks but if you set
19       your disks to spin down after a few seconds you  may  damage  the  disk
20       over time due to the stress the spin-up causes on the spindle motor and
21       bearings. It seems that manufacturers recommend a minimum idle time  of
22       3-5 minutes, the default in hd-idle is 10 minutes.
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24       One  more  word  of caution: hd-idle will spin down any disk accessible
25       via the SCSI layer (USB, IEEE1394, ...) but it will NOT work with  real
26       SCSI  disks  because  they  won't  spin up automatically. Thus it's not
27       called scsi-idle and I don't recommend using it on a real  SCSI  system
28       unless you have a kernel patch that automatically starts the SCSI disks
29       after receiving a sense buffer indicating the disk  has  been  stopped.
30       Without  such a patch, real SCSI disks won't start again and you can as
31       well pull the plug.
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OPTIONS

34       -a name
35              Set device name of disks  for  subsequent  idle-time  parameters
36              (-i).   This  parameter  is optional in the sense that there's a
37              default entry for all disks which are not named otherwise by us‐
38              ing   this   parameter.   This  can  also  be  a  symlink  (e.g.
39              /dev/disk/by-uuid/...)
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41       -i idle_time
42              Idle time in seconds for the currently named disk(s) (-a <name>)
43              or for all disks.
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45       -l logfile
46              Name  of logfile (written only after a disk has spun up). Please
47              note that this option might cause the disk which holds the  log‐
48              file  to  spin  up  just because another disk had some activity.
49              This option should not be used on systems  with  more  than  one
50              disk  except  for  tuning purposes. On single-disk systems, this
51              option should not cause any additional spinups.
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53       -t disk
54              Spin-down the specfified disk immediately and exit.
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56       -d     Debug mode. This will prevent hd-idle from becoming a daemon and
57              print debugging info to stdout/stderr
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59       -n     No-daemon mode. This will prevent hd-idle from becoming a daemon
60              and print logging informatin to stdout. Most useful  if  hd-idle
61              is started by systemd.
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63       -h     Print usage information.
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DISK SELECTION

66       The  parameter -a can be used to set a filter on the disk's device name
67       (omit /dev/) for subsequent idle-time  settings.  The  default  is  all
68       disks:
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70       1)     A -i option before the first -a option will set the default idle
71              time; hence, compatibility with previous releases of hd-idle  is
72              maintained.
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74       2)     In order to disable spin-down of disks per default, and then re-
75              enable spin-down on selected disks, set the default idle time to
76              0.
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EXAMPLE

79       hd-idle -i 0 -a sda -i 300 -a sdb -i 1200
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81       This  example  sets  the  default  idle time to 0 (meaning hd-idle will
82       never try to spin down a disk), then sets explicit idle times for disks
83       which have the string "sda" or "sdb" in their device name.
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AUTHOR

86       hd-idle was written by Chistian Mueller <chris@mumac.de>
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88       This manual page was written by Christian Mueller <chris@mumac.de>, for
89       the Debian project (and may be used by others).
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93                              September 29, 2011                    HD-IDLE(1)
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