Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

In Fedora 17, when I want to plug my USB hard disk out, I can only unmount it. But the problem is that the hard drive won't be powered off so that I can plug it out.

In some other distros like Ubuntu there is a Safely Remove option which powers the hard drive off.

How can I fix that?

share|improve this question
Does hdparm -y /dev/sdX work? – slhck Nov 11 '12 at 19:56
Nope sir. This command removes the drive name from nautilus menu but does not power it off. – Mehrdad Nov 11 '12 at 20:44
Hey guys, I found it myself. I needed to run the command: udisks --detach /dev/sdX I will post it as an answer as soon as the 8-hour time limit for forum newbies passes. – Mehrdad Nov 11 '12 at 20:51
Alright, great. Glad you solved the problem. – Josiah Nov 12 '12 at 2:18
up vote 5 down vote accepted

After a lot of web surfing I came across the solution suggested by someone in Thank you everybody. I just needed to install udisks package! To power off my hard disk I have to enter the following command in terminal after unmounting all of its partitions:

udisks --detach /dev/sdX
share|improve this answer
Haven't tested this (used udisks --unmount) and udisks -h doesn't list --detach for me. Fedora 19. – hakre Aug 27 '13 at 19:30
As of ubuntu 15.10, this seems to be udisksctl power-off -b /dev/sdb. BTW, as a response, my HDD switched off its light but still emitted noise and vibration until I physically plugged it off. – gluk47 Oct 30 '15 at 23:50

There is no safe removal button for the USB drive. You can eject the USB drive by clicking the small triangle which is on the side of the USB drive.

For ejecting a flash drive follow these steps:

  1. First see the USB drive by entering this command:

    fdisk -l
  2. Assuming your USB drive is /dev/sdb1, eject it with the following command:

    umount /dev/sdb1


    eject /dev/sdb1 

This will allow you to safely remove your USB drive.

share|improve this answer
The "little triangle" can be found under Activities > Files and by locating the USB drive on the left pane. The icon is to the right of the USB drive's label. – Matthew Walker Jun 18 '15 at 5:53


eject /dev/sdX

where X is the letter of your device.


You can find all available drive letters by using fdisk -l.

share|improve this answer
Could you explain how to find out what the device letter is? I would assume this can be confused quite easily. – slhck Nov 11 '12 at 18:52
This did not help. I also checked eject's man page in which it is written that this command does the same as umount according to the device in use. – Mehrdad Nov 11 '12 at 19:01
eject /media/THE_DISK should also work (if it is mounted there). @Mehrdad, don't believe too much what manuals say. They might be wron (report to bugzilla if so). – vonbrand Feb 25 '13 at 2:57
@Josiah please mention fdisk -l in your answer as the means to check drive letters, or any other mean you find appropriate. – Lorenzo Von Matterhorn Apr 20 '13 at 20:22
@Znau. Added, thanks for that! – Josiah Apr 20 '13 at 20:35

Enter the following command to power off the hard drive:

hdparm -y /dev/sdx
share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.