I have 2 HDDs in my PC. Ubuntu is turning off the secondary HDD very quickly after about 15 minutes, which is short for me. I need to control this time. How can I do it?

I tried GNOME power management but did not find it useful.

12 Answers 12


Have a look at hdparm.

From the manual (man hdparm on the command line):

-S Set the standby (spindown) timeout for the drive. This value is used by the drive to determine how long to wait (with no disk activity) before turning off the spindle motor to save power. Under such circumstances, the drive may take as long as 30 seconds to respond to a subsequent disk access, though most drives are much quicker.

The encoding of the timeout value is somewhat peculiar. A value of zero means "timeouts are disabled": the device will not automatically enter standby mode. Values from 1 to 240 specify multiples of 5 seconds, yielding timeouts from 5 seconds to 20 minutes. Values from 241 to 251 specify from 1 to 11 units of 30 minutes, yielding timeouts from 30 minutes to 5.5 hours. A value of 252 signifies a timeout of 21 minutes. A value of 253 sets a vendor-defined timeout period between 8 and 12 hours, and the value 254 is reserved. 255 is interpreted as 21 minutes plus 15 seconds. Note that some older drives may have very different interpretations of these values.

So sudo hdparm -I /dev/sdb | grep level will show the current spindown value, for example:

Advanced power management level: 254

From the manual: 254 is reserved so I expect it to be Ubuntu's default (can anyone confirm/expand on this please?)


sudo hdparm -S 25 /dev/sdb = spindown after 25*5 seconds.

sudo hdparm -S 245 /dev/sdb = spindown after (245-240)*30 minutes.

  • 5
    Regarding lzap's answer you seem to grep for APM (-B parm) but talk about -S the spindown. Do you also know something about APM? – turbo Mar 13 '12 at 18:09
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    The current -B setting is shown as indicated above. How can I see the current -S setting? – SabreWolfy Jun 22 '12 at 22:57
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    sudo hdparm -y /dev/sdb kills the beast immediately – siamii Mar 3 '13 at 23:20
  • 1
    @SabreWolfy I've asked that as a separate question: How can I find out the current drive spin-down time? – ændrük Apr 13 '13 at 4:12
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    When I use "-S" to set a spindown time, it tells me it's going to step standby to the time I specify, but when I immediately read it back with "-I" it tells me the level is 254. – Michael Aug 28 '18 at 4:46

Disk Utility -> select HDD drive -> click on the "More actions..." icon on the top right corner -> Drive settings...

Mine is looks like this: screenshot

  • 10
    Easiest by far, thanks! (BTW the package you need to install if you don't have this is gnome-disk-utility. – Gerhard Burger Feb 10 '14 at 21:14
  • way to go linux! +1 – neu-rah Jul 22 '15 at 7:29
  • Yes, extremely easy - glad this is here. – Zzzach... May 15 '16 at 2:16
  • @Ray You, sir, are awesome! I had basically no hope that it would work for an external HDD but it did! – UTF-8 Oct 12 '16 at 11:15
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    Why most of tips involve error prone file editing or console operations, while user friendly tools like this already exits! – WooYek Jul 8 '17 at 13:37

If you're interested on do the hdparm's setting persistent between reboots, instead of adding it to the crontab, you can use the /etc/hdparm.conf. I have the following, note the use of capital S, not lowercase:

command_line {
    hdparm -S 25 /dev/disk/by-uuid/f6c52265-d89f-43a4-b03b-302c3dadb215 

Add that line replacing the UUID by yours, or also you may specify the device using /dev/sdX format. You can find out your disk's UUID with the command sudo blkid.

  • 4
    Is it correct to use command_line nowadays? I have different examples in my /etc/hdparm? – Dims Oct 22 '14 at 7:19
  • 3
    Ondra Žižka's answer seems to be more up to date. – Raphael Apr 28 '18 at 17:28
  1. Find your disk's UUID.

    sudo lsblk --output NAME,FSTYPE,LABEL,UUID,MODE
  2. Edit /etc/hdparm.conf

    sudo -H gedit /etc/hdparm.conf  # Be careful from now on
  3. Look for spindown-time or your disk settings section.

    /dev/disk/by-label/4TB {
        spindown_time = 1200
  4. I prefer to refer to the disk by UUID which remains the same across different installations (unless you change it in the HW itself).

    /dev/disk/by-uuid/91e32677-0656-45b8-bcf5-14acce39d9c2 {
        spindown_time = 1200
  5. If the init script causes boot problems, you can pass nohdparm on the kernel command line, and the script will not be run.

  • What are the units for that parameter? – detly Aug 6 '16 at 8:55
  • IIRC, it's seconds. Or maybe this is the parameter which had wild rules like "if it's under 10, then its tens of seconds, if under 100, then it's minutes", and such. I'd need to find. – Ondra Žižka Aug 9 '16 at 13:01
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    It's not units, check this: wiki.archlinux.org/index.php/Hdparm – Ondra Žižka Aug 9 '16 at 13:07
  • Cheers, for some reason I couldn't find it in man hdparm.conf. – detly Aug 9 '16 at 13:09
  • man hdparm.conf indirectly reads that the value is passed to -S hence for values < 255 should be compatible with rule in the top answer. Any further information is welcomed. – dma_k Jan 18 '18 at 17:23

After spending hours and hours I discovered that my WDC drive do not support hdparm -S command, no matter idle3 attribute value (google: idle3ctl). And that is common problem with WD drives. But I'm pleased to announce that hd-idle (http://hd-idle.sourceforge.net/) works flawlessly. If installed from dpkg-builded package (see Installation notes), it creates daemon on both ubuntu and debian (config is in /etc/default/hd-idle). Works well after resuming from hibernation as well.

mc default # ps aux | grep hd-idle | grep -v grep | cut -c 66- ; for f in [a-d] ; do hdparm -C /dev/sd$f | grep -v "^$" ; done
/usr/sbin/hd-idle -i 1800 -a sdc -i 600 -a sdd -i 60 -l /var/log/hd-idle.log
 drive state is:  active/idle
 drive state is:  standby
 drive state is:  standby
 drive state is:  standby


I discovered that the spindown behavior of Samsung HD204UI depends on the APM level (hdparm -B). If the APM level is 127, the spindown timeout is 10 s. If the APM level is 150, the spindown timeout is defined by the -S option.


I add something like:

@reboot sudo hdparm -S244 /dev/disk/by-uuid/71492809-e463-41fa-99e2-c09e9ca90c8e  > /dev/null 2> /dev/null

to root's crontab. Using uuid is better I think because sda/sdb etc. seems to change with every reboot


In Ubuntu 14.04

Disks > highlight drive > click the gear in the upper right hand corner > Drive Settings > now you have Standby, APM, AAM and Write Cache settings in an easy to use GUI!

  • How do you make this work? I have set this, and after reboot if i go back in it has remembered that the drive should power down, but it never does. hdparm -C always shows it is active and only running hdparm -S xxx from the commandline makes it work. – dan carter Jul 20 '14 at 11:10
  • 1
    Where do you find "Disks"? – nealmcb Jan 14 '15 at 1:14

I had no luck with hdparm on an external HDD mounted in a USB enclosure, which I use to serve media with minidlna.

I came across an idea from here: https://serverfault.com/questions/562738/keeping-usb-backup-drive-from-sleeping-while-mounted

Best results come from using the disk's uuid, which you can find with:

sudo blkid

The following method does require root access, but so does hdparm. This uses crontab to read a random block from the drive every 5 minutes and ignores all messages. To make sure you have the right UUID, test it on the command line like this (make sure you use your desired UUID, not this one):

sudo dd if=/dev/disk/by-uuid/f01df4b5-6865-476a-8d3b-597cbd886d41 of=/dev/null count=1 skip=$RANDOM

You should see output like this:

1+0 records in
1+0 records out
512 bytes copied, 0.000738308 s, 693 kB/s`

To suppress this message, which could end up getting written somewhere, potentially the / filesystem (which is on an SSD in my case), below is what I'm using in the root crontab. You get there with

sudo crontab -e

Then, under the comments:

*/5 * * * * bash -c 'dd if=/dev/disk/by-uuid/f01df4b5-6865-476a-8d3b-597cbd886d41 of=/dev/null count=1 skip=$RANDOM' >/dev/null 2>&1

Hope this helps someone else with similar issues. Unfortunately, this still gets written to the syslog, but there are potentially ways to suppress that; see this ServerFault post.

[edit] 2017-01-07 09:02:

I was able to suppress these messages by editing /etc/rsyslog.d/50-default.conf to change this line:

*.*;auth,authpriv.none -/var/log/syslog

to this:

*.*;cron,auth,authpriv.none -/var/log/syslog

Unfortunately, this suppresses all cron messages; I could not get cron to redirect logging off the root filesystem (which is on an aging SSD in my case, so I want to limit writes), but as this is just a home server, I am probably not missing out on much. Would definitely not recommend this strategy for a production machine.


On Debian, with WD drives, I find that setting any level with hdparm -S results in the drive returning a level 254 on subsequent hdparm -I. So I'm really not sure if they're spinning down or not. I think they are still spinning down.

These drives are on a server array, and I really don't want them to ever spin down. In the past I've kludged this by setting a cron job to update a file every few minutes.


on ubuntu 18.04 to 20.04, you can change drive setting standby timeout at:
search Disks in the launcher > select your disk > click on ⋮ at menu bar next to minimize the window button > Drive Settings > use slider to set timeout

Screenshot on ubuntu 20.04


An important note: unlike the main answer, it seems that

sudo hdparm -I /dev/sdb | grep level 
# Advanced power management level: 254

does not show the current spindown value (that we can set with hdparm -S, as desired by OP), but rather displays the value set with hdparm -M:

hdparm -M 128   # Set acoustic management to 'quiet'
hdparm -M 254   # Set acoustic management to 'fast'

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