VirtualBox shared folder is accessible but not workable

Question

On my host system (Windows 8 Pro 64 Bit), I installed VirtualBox (4.2.12) and installed Ubuntu 12.04 32 Bit as guest system. I also installed the VirtualBox guest utilities to create shared folders.

Now, after creating a shared folder, I added my user id to the group vboxsf, which is the owner of the shared folder with

sudo usermod -a -G vboxsf <my-user-id>

After a re-login to the Ubuntu system, I can access the shared folder and create a text file in it. But when using a text editor like gedit or Geany, I encounter a strange problem. When I try to save the file, the original file will be removed from the disk and gedit tells me

Could not save the file /media/sf_shared_folder/test.txt and

Unexpected error: Error renaming temporary file: Text file busy

Why there are conflicts when I am already in the group? And how to solve them?

Solution

I experienced the same issue. My setup: VirtualBox 4.2.12 with Ubuntu 13.04 guest running on W7SP1 host, mounted Windows folder with fstab like this

dev /home/dregad/dev    vboxsf  auto,rw,uid=dregad,gid=dregad,umask=0022,dmode=0755,fmode=0644  0   0

I'm using Geany. Saving the file fails with similar symptoms as described in the question above for gedit (which fails too). Error message as follows:

Error saving file.
Error renaming temporary file: Text file busy
The file on disk may now be truncated!

My solution for Geany:

• Edit / Preferences
• Select Various tab
• scroll down and check the box for use_atomic_file_saving
• click OK

I don't use it much, so not sure if gedit provides a similar trick, but FWIW, you may want to have a look at this stackexchange question as it offers a workaround.

Comments

[ignis]

Workaround: does it work with mount -t vboxsf uid=1000,gid=1000 <folder-name> <mount-point>, possibly without you being in the vboxsf group?

[Takkat]

You should reboot your Ubuntu after you changed a user's group membership.