1HD-IDLE(1) General Commands Manual HD-IDLE(1)
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6 hd-idle - spin down idle hard disks
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9 hd-idle [options]
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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.
16 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.
23 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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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/...)
40 -i idle_time
42 Idle time in seconds for the currently named disk(s) (-a <name>)
43 or for all disks.
44 -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.
52 -t disk
54 Spin-down the specfified disk immediately and exit.
55 -d Debug mode. This will prevent hd-idle from becoming a daemon and
57 print debugging info to stdout/stderr
58 -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.
62 -h Print usage information.
64
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:
69 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.
73 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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79 hd-idle -i 0 -a sda -i 300 -a sdb -i 1200
80 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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86 hd-idle was written by Chistian Mueller <chris@mumac.de>
87 This manual page was written by Christian Mueller <chris@mumac.de>, for
89 the Debian project (and may be used by others).
90 September 29, 2011 HD-IDLE(1)