Cannot install Ubuntu with UNetBootin

system-installation 11.04 ubiquity unetbootin

11,365

Solution 1

It is a bug in Ubiquity:

I eventually found those threads after a long, really non-trivial search... Interesting workarounds are listed there. However I won't vouch for them (see comment). Be careful if you need install Ubuntu from an ISO image directly from your disk!

Solution 2

I have also spent hours trying to fix this, even though my problem did not start with UNetBootin. However I got the same result: the installer just quit and said that thing about not being able to unmount /cdrom

Finally the right solution was found at https://help.ubuntu.com/community/Installation/FromLinux

Specifically, do this:

Note2: Instead of using 'workaround', an alternative is to modify the file /etc/mtab by erasing the line that specifies the partition where the cdrom is mounted. This way the kernel thinks thats the /cdrom is not mounted and will not show the advice when installing ubuntu. I think this procedure is less dangerous than the one in the previus note.

Do this before you start the installer. If that does not work, try to do this right before you press the "Install Now" button.

Solution 3

For me

sudo umount -l -r -f /cdrom

worked like a charm

11,365

Luc125

Updated on September 18, 2022

Comments

Luc125 over 1 year
I have tried several times to install Natty on its own partition on my laptop (WinXP, Intel x86) using UNetBootin, but it always fail.

There is a dialog box:
```
Failed to unmount partitions

The installer needs to commit changes to partition tables,
but cannot do so because partitions on the following could
not be unmounted.

/cdrom

Please close any applications using these mount points.

Would you like the installer to try to unmount these partitions again?
```
If I click on "continue" Ubiquity will hang up, that is, the slideshow will play forever. I do not have a built-in optical drive and I'm not currently using any peripheral.

I have tried sudo umount /cdrom it says that cdrom is busy. Then the command fuser /cdrom returns "Stale NFS file handle".

How can I work around this to install Ubuntu?
- nilsonneto over 12 years
  
  can you add a link to a screenshot showing the error?
- Luc125 over 12 years
  
  I have tried but I can no longer open my browser once the install procedure has started, and everything I save is lost when I return to XP...
- Jason Southwell over 12 years
  
  Are you able to install using another method?
- Petriborg over 12 years
  
  Very similar question on superuser. My answer, I believe, may help. superuser.com/questions/152490/…
- Luc125 over 12 years
  
  Not really... But it's ok now. Thank you all for your help! And, euh, sorry for not responding for so long, my laptop didn't work anymore.
Luc125 over 12 years

I tried one of the suggested workaround but it didn't work for me. Maybe I didn't performed it correctly? Anyway, Ubiquity did not freeze this time, but simply crashed. Subsequently I could no longer start my laptop. Visibly the crash had introduced an error in the config of the bootloader (GRUB). This time I really had to get a CD drive.
volni over 12 years

This worked for me Cray, thank you! I know this isn't stackexchange etiquette but this problem has been driving me nuts!
Admin over 11 years

This fix still applies to 12.04. Thanks a million.
ThorSummoner almost 9 years

This seems to still appliy to 14.04 and 15.05. But even with out this error I'm getting other errors when installing.
Matt Zabojnik about 4 years

This worked perfectly. This should be marked as the accepted answer.