topic Re: No clue how the NFS mount points are mounted in Operating System - Linux

No clue how the NFS mount points are mounted

Senthil_N — Mon, 11 Nov 2013 04:27:03 GMT

Hi All,

# df -hP /opt/linuxdepots/
Filesystem Size Used Avail Use% Mounted on
uxlinux:/sg/opt/linuxdepots 354G 34G 302G 11% /autofs/linuxdepots

Here both "/autofs/linuxdepots" and "/opt/linuxdepots/" are same. But my query is /autofs/linuxdepots is configured part of autofs. but there is no clue how /opt/linuxdepots/ is configure.

Can any one throw some light on this.

P.S. This thread has been moved from Linux > System Admin to Linux > networking. - Hp Forum Moderator

Re: No clue how the NFS mount points are mounted

Matti_Kurkela — Mon, 11 Nov 2013 14:41:24 GMT

It is probably caused by symbolic links (sort of similar to Windows shortcuts).

Please run this command:

ls -ld /opt /opt/linuxdepots

Either the /opt directory or /opt/linuxdepots may be a symbolic link.

Symbolic links are identified in the ls -ld listing by having a lower-case letter "l" in the first column. They will also have their target displayed at the end of the line. You will probably see something like this:

lrwxrwxrwx  1 root  root  <timestamp> /opt/linuxdepots -> /autofs/linuxdepots

or

lrwxrwxrwx  1 root  root  <timestamp> /opt -> /autofs

The permissions of a symbolic link are normally ignored, and the permissions of the actual file will be used instead.

This is why the permissions of symbolic links are usually always "lrwxrwxrwx" and they cannot be easily changed.

(Some very special situations may produce symbolic links with different permissions, but those situations should be regarded as programming errors or minor filesystem corruption.)

Symbolic links can be created with the "ln -s" command, and deleted with a regular "rm" command.

The use of "ln -s" is conceptually similar to the "cp" command:

"cp <source> <destination>" makes a copy of <source> at <destination>,

and "ln -s <source> <destination>" makes a link to <source> appear at <destination>.

In both cases, if <destination> is a directory, the copy/link will be created using its original file/directory name, but if <destination> is a non-existent file in a valid directory, then the copy/link will be named <destination> instead of its original file/directory name.

Re: No clue how the NFS mount points are mounted

Dennis Handly — Mon, 11 Nov 2013 17:48:44 GMT

>"ln -s" is conceptually similar to the "cp" command:

>"ln -s <source> <destination>" makes a link to <source> appear at <destination>.

Hmm, I conceptualize it exactly the reverse. I.e.:

ln -s <target of symlink> <symlink>

Though without the -s, for hardlinks, there is a well defined source.

Re: No clue how the NFS mount points are mounted

Senthil_N — Tue, 12 Nov 2013 22:30:59 GMT

Hi Matti and Dennis,

It does not look like symbolic link. Please find the output.

# ll -d /opt/linuxdepots/
dr-xr-xr-x 58 root root 3072 Nov 12 15:12 /opt/linuxdepots/

# ll -d /autofs/linuxdepots/
dr-xr-xr-x 58 root root 3072 Nov 12 15:12 /autofs/linuxdepots/

Re: No clue how the NFS mount points are mounted

Matti_Kurkela — Sat, 16 Nov 2013 22:12:41 GMT

> # ll -d /opt/linuxdepots/
> dr-xr-xr-x 58 root root 3072 Nov 12 15:12 /opt/linuxdepots/

Leave out the last slash from the command. When trying to check the information of a directory symlink, it can make a difference.

Please try this command EXACTLY:

# ll -d /opt/linuxdepots

Re: No clue how the NFS mount points are mounted

Senthil_N — Wed, 20 Nov 2013 21:57:57 GMT

Hi Matti,

Yes you are correct.

Now it is showing the original directory.

Thanks a lot.