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Last modified by Сергей Коршунов on 2023/06/08 18:51
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1 Unmounting disks in the Linux command line is not complicated. All you have to do is to use the umount command:
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3 {{{umount target}}}
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5 But once in a while, you'll come across an error that says **'umount: target is busy'**:
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7 [[~[~[image:https://linuxhandbook.com/content/images/2023/03/target-is-busy-while-unmounting-the-drive-in-Linux.png~|~|alt="target is busy while unmounting the drive in Linux" height="151" width="837"~]~]>>url:https://linuxhandbook.com/content/images/2023/03/target-is-busy-while-unmounting-the-drive-in-Linux.png]]
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9 So how are you supposed to solve this issue?
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11 Well, before solving this issue, let me share the reason behind this problem first.
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13 == The reason behind Umount target is busy ==
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15 The reason is quite simple! The target device is still in use.
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17 With enough permissions, any process might be utilizing that drive that you want to unmount, and to prevent data loss, the kernel won't allow you to unmount.
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19 == How to solve Umount target is busy in Linux ==
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21 ⚠️
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23 If an ongoing data transfer occurs in the background, you may lose your data by forcefully unmounting your drive.
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25 There are times when you want to unmount the drive at any cost. Perhaps the drive isn't responding for some reason and you want to unmount it.
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27 In this tutorial, I will share three ways to unmount the target:
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29 * By killing the process itself
30 * Using force unmount
31 * Using the lazy unmount
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33 Let's start with the first method.
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35 === Method 1: Unmout target by killing the process itself (recommended) ===
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37 This is the best way of unmounting the target in my opinion as you are eventually killing the process itself.
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39 The first step is to [[find the PID of the process>>url:https://linuxhandbook.com/find-process-id/]] that causes the problems.
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41 To do so, I will be [[using the lsof command>>url:https://linuxhandbook.com/lsof-command/]] in the following manner:
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43 {{{sudo lsof /Path/to/target}}}
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45 [[~[~[image:https://linuxhandbook.com/content/images/2023/03/find-PID-of-the-mounted-drive-1.png~|~|alt="find PID of the mounted drive" height="276" width="896"~]~]>>url:https://linuxhandbook.com/content/images/2023/03/find-PID-of-the-mounted-drive-1.png]]
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47 Once you get the PID, it's quite simple to [[force kill the process>>url:https://linuxhandbook.com/kill-process/]]:
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49 {{{sudo kill -9 [PID]}}}
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51 And now, you should be able to unmount the drive easily:
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53 [[~[~[image:https://linuxhandbook.com/content/images/2023/03/kill-the-process-and-unmount-the-drive.png~|~|alt="kill the process and unmount the drive" height="152" width="896"~]~]>>url:https://linuxhandbook.com/content/images/2023/03/kill-the-process-and-unmount-the-drive.png]]
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55 Pretty neat way. Isn't it?
56
57 === Method 2: Using force unmount (for Network File Systems) ===
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59 The force unmount option is mainly preferred by those who are dealing with network file systems.
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61 So **it may NOT give you the expected results with your local file system.**
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63 To use the force unmount, you will have to use the same old umount command but with the -f flag:
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65 {{{sudo umount -f /Path/to/target}}}
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67 [[~[~[image:https://linuxhandbook.com/content/images/2023/03/use-force-unmount-to-solve-target-is-busy-error.png~|~|alt="use force unmount to solve target is busy error" height="167" width="837"~]~]>>url:https://linuxhandbook.com/content/images/2023/03/use-force-unmount-to-solve-target-is-busy-error.png]]
68
69 === Method 3: Using the lazy unmount (Schrödinger's unmount) ===
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71 📄
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73 This option does not actually unmount your target but just removes the target from the namespace. And will unmount the target when the drive is not being utilized anymore!
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75 It is more of a Schrödinger's mount when you can never be sure of whether the filesystem is unmounted or not!
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77 So why am I even adding this to the solution's list? Well, this is the least harmful way of unmounting your stubborn drive.
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79 To use the lazy unmount, you will have to use the -l flag with the umount command as shown:
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81 {{{sudo umount -l /Path/to/target}}}
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83 [[~[~[image:https://linuxhandbook.com/content/images/2023/03/using-the-lazy-unmount-to-solve-the-target-is-busy-in-linux.png~|~|alt="using the lazy unmount to solve the target is busy in linux" height="167" width="837"~]~]>>url:https://linuxhandbook.com/content/images/2023/03/using-the-lazy-unmount-to-solve-the-target-is-busy-in-linux.png]]
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85 And here you have it!