Recently I came to know about the mount --bind command but there is something that I can't understand clearly. Suppose I have a disk partition and I mounted it to a mount point /bkup using this command.

sudo mount /dev/sdd1 /bkup

If I want to make that /home/bkup directory appear as ~/bkup, I could do

sudo mount --bind /bkup ~/bkup

But how is it different from

ln -s /bkup ~/bkup

in effect? Why should I use mount --bind when I can do the same thing with ln -s command?

1

1 Answer

mount --bind is more like an equivalent of a "hard link" to a directory (well, you cannot create hard links to directories, but this is closest you can get), while symbolic link is... well, a symbolic link.

Myself I found two cases where the difference may be important:

1. running some service in a chroot. Symbolic links from inside a chroot jail to outside of a chroot jail don't work, while mount --bind works.

2. sharing some directory over a network. You cannot share a symbolic link, but you can share directory mounted over mount --bind.

You must also be very careful with programs that by design distinguish between symbolic links and actual directories, like rsync. Trying to run rsync on a symbolic link to a directory may give you completely other results than you expect.

Your Answer

Sign up or log in

Sign up using Google Sign up using Facebook Sign up using Email and Password Submit

Post as a guest

Post Your Answer Discard

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy