Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

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

I have the following share setup on my Ubuntu machine

# From /etc/fstab
// /home/USER/SHARE/media cifs username=USERNAME,password=PASSWORD,_netdev,uid=USER,gid=users 0 0

However when I try to create a symlink in the mounted directory I get the following error.

$ ln -s file sym_file
ln: creating symbolic link `sym_file': Operation not supported

I've tried this from my Mac which is also communicating over the same protocol and the creation of syms is allowed? Does anyone know what's prevent me from doing this under Linux.

share|improve this question

According to mount.cifs(8), you need ver. >=1.40 of the kernel module in order for this to work:

When the CIFS Unix Extensions are not negotiated, attempt to create device files and fifos in a format compatible with Services for Unix (SFU). In addition retrieve bits 10-12 of the mode via the SETFILEBITS extended attribute (as SFU does). In the future the bottom 9 bits of the mode mode also will be emulated using queries of the security descriptor (ACL). [NB: requires version 1.39 or later of the CIFS VFS. To recognize symlinks and be able to create symlinks in an SFU interoperable form requires version 1.40 or later of the CIFS VFS kernel module.

share|improve this answer
Any ideas how you would go about upgrading the "CIFS VFS kernel module" or even find out what version I'm currently running with? – Jamie Feb 9 '10 at 21:35
Hmm, on ubuntu 9.10 it looks like the version is 1.60, so it shouldn't be the problem. to check the ver.: $ modinfo cifs – Sunny Feb 10 '10 at 18:03
I'm also on ver1.60 so it doesn't seem to be the issue. Any other ideas? – Jamie Feb 10 '10 at 19:28
Actually, I don't know how you can do it on Mac. I just re-read your question, and what you do seems impossible. The simlink is read/interpret by the client, not the server, and you are trying to do it on the server. Can you provide the output of mount on the Mac, and all the commands you execute to make it work? – Sunny Feb 10 '10 at 22:01
Unfortunately it's actually mounted via the gui on the mac so I'm not sure what useful details I can provide. However it is definitely using the the smb:// protocol to connect. My confusion is that surely smb is quite a common protocol for unix systems to connect to, is the symlink issue not a common one? – Jamie Feb 11 '10 at 13:21

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .