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I did something incredibly stupid: while tinkering with mount / umount trying to relocate some space, I did as I read on one website, and dit

sudo umount -f /mnt

(I don't remember whether I used -f or some other command to force it)

And when I did it, it suddenly crashed ubuntu. Then I couldn't access my profile (because of lack of home directory) I tried this: Deleted home directory. Please help

And it worked, but the problem is, that this new home folder doesn't have any of my old files.

So the question is: Is this unmounting reversible? Or were my files deleted?

To rephrase the question: what could happen while unmounting /mnt ? What can I do to link my old home folder with new?

Typing 

editor /etc/fstab

got 

file system < mount point < type
proc /proc
/host/ubuntu/disks/root.disk /
/host/ubuntu/disks/swap.disk none

(sorry it took so long, I had problems accesing it)

Another question: What is the difference with /etc/fstab data and the data which can be retrieved by df -h? I manipulated with filesystem using info from df -h and now the info from fstab confuses me

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Jakub Bartczuk
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    If this isn't a standard filesystem setup (if you've got /home from another partition for example), please edit your question to include the content of `/etc/fstab` – Oli Aug 23 '13 at 11:45
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    Please do what Oli asked above, we cannot guess. And if you want to rephrase your question (not advisable at the moment) then do it by **editing the question**, not in a comment. – guntbert Aug 23 '13 at 12:25
  • What is this system? That fstab is most irregular. – Oli Aug 23 '13 at 12:36
  • You mean is this NTFS or something else? It's NTFS – Jakub Bartczuk Aug 23 '13 at 12:41
  • I mean that most systems mount a device on / rather than another path (relative to /host/)... When you say this is NTFS, do you mean it's a Wubi install? – Oli Aug 23 '13 at 12:45
  • It is Wubi install. – Jakub Bartczuk Aug 23 '13 at 12:46
  • In a Wubi install, it is possible that the force unmount corrupted the root.disk file itself - you may be able to recover it by booting into Windows and running chkdsk from there - see http://askubuntu.com/questions/228709/ubuntu-12-04-wubi-not-starting-root-disk-corrupted – steeldriver Aug 23 '13 at 13:24
  • @steeldriver I did chkdsk (strange, when I did it before, nothing happened). Now when I enter linux I get The disk contains an unclean file system (0,0) The file system wasn't safely closed on Windows. Fixing. But it actually doesn't fix anything. – Jakub Bartczuk Aug 23 '13 at 18:09

1 Answers1

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Mounting and unmounting is a runtime thing. They don't write anything to disk - they just alter the in-kernel way the filesystem is mapped. Mouts are loaded from /etc/fstab so unless you've changed that, just restarting the computer would get things back in order. sudo mount -a might even work. It might not.

What would happen on a normal system if you forcefully unmounted /mnt is you would unmount the root filesystem (they would be the same device). The computer would grind to a halt near-instantaneously. On a normal computer, restarting would follow /etc/fstab and remount / (and everything in it, including /mnt) and put everything back in the right place.

In short: Reboot (or boot to a LiveCD for added safety) then see what the damage actually is.

Oli
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  • "Mounting and unmounting is a runtime thing. They don't write anything to disk - they just alter the in-kernel way the filesystem is mapped. " I'm clueless. I don't understand why it crashed ubuntu. Tried restarting - didn't do any good. I also tried "mount -a". Would appreciate any help on what should I google (how to extract important information about fstab) – Jakub Bartczuk Aug 23 '13 at 11:54
  • Also, what's happening with the files when one umounts /mnt? Is this actually deleted, or does it only change location on physical disk? How to comprehend answer to this question? – Jakub Bartczuk Aug 23 '13 at 11:57
  • What do you mean restart didn't do any good? What are you left with? – Oli Aug 23 '13 at 11:59
  • ***Nothing*** happens to the files on disk when you unmount something. That's my point. They just become inaccessible through their old mountpoint until they're mounted again (which should be boot). – Oli Aug 23 '13 at 12:01
  • After creating home folder, as in provided link, I am able to access, but I don't see my old files. I'm also getting errors when I try to install something (as it needs access to nonaccessible files). If nothing happens, then the problem is to access them again - but I don't know how to do it. Rebooting didn't help. When I first rebooted I couldn't even enter desktop, as there was something like 'couldn't access home directory', but using the link which I pasted helped. – Jakub Bartczuk Aug 23 '13 at 12:14