Directory sync across SSHFS involving symlinks

Question

I have 2 Ubuntu Linux boxes with similar directory structures, LX02 and LX04. When I ssh from a terminal on LX02 to LX04 and go to my main scripting directory, /root/sbin, I see a different set of subdirectories than when I go the same directory from a terminal session on LX04. Why?

DETAILS
Both machines have a /0 directory that contains mountpoint directories for each remote host as in...

/0/LX02
/0/LX04

/etc/fstab contains entries to mount the remote host's root (/) directory to these. There is a 'mount bind' entry to mount the local (/) directory which avoids special coding for the local host in scripts.

/root/sbin is a symlink to /usr/local/sbin on each machine.

The local /root/sbin directory on LX02 looks like...

 root@LX02:/  cd /root/sbin

 root@LX02:~/sbin  ls -l | grep '^d'

drwxr-x--- 2 root root  4096 2011-07-16 00:49 Archives-sbin-20110825
drwxr-x--- 2 root root  4096 2010-07-28 08:13 lst
drwxr-xr-x 2 root root  4096 2012-04-11 09:28 Misc
drwxr-xr-x 2 root root  4096 2012-04-11 09:28 Slates
drwxr-xr-x 2 root root  4096 2012-04-11 09:28 Tomboy
drwxr-xr-x 2 root root  4096 2012-04-11 09:28 Ubuntu_8.04
drwxr-x--- 2 root root  4096 2010-07-28 08:13 www
drwxr-xr-x 2 root root  4096 2012-09-27 12:48 zim

Going to /0/LX04/root/sbin from an LX02 terminal session results in...

 root@LX02:/0/LX04/root/sbin  cd /0/LX04/root/sbin

 root@LX02:/0/LX04/root/sbin  ls -l | grep '^d'

drwxr-x--- 2 root root  4096 2011-07-16 00:49 Archives-sbin-20110825
drwxr-x--- 2 root root  4096 2010-07-28 08:13 lst
drwxr-xr-x 2 root root  4096 2012-04-11 09:28 Misc
drwxr-xr-x 2 root root  4096 2012-04-11 09:28 Slates
drwxr-xr-x 2 root root  4096 2012-04-11 09:28 Tomboy
drwxr-xr-x 2 root root  4096 2012-04-11 09:28 Ubuntu_8.04
drwxr-x--- 2 root root  4096 2010-07-28 08:13 www
drwxr-xr-x 2 root root  4096 2012-09-27 12:48 zim

However, the /root/sbin directory on LX04 actually looks like...

 root@LX04:/  cd /root/sbin

 root@LX04:~/sbin  ls -l | grep '^d'

drwx------ 4 root root 12288 2011-12-23 03:23 Archives
drwx------ 2 root root  4096 2011-07-16 00:49 Archives-sbin-20110825
drwxr-xr-x 3 root root  4096 2012-11-14 00:22 Examples
drwxr-x--- 2 root root  4096 2011-04-29 13:50 fnc
drwxr-x--- 2 root root  4096 2011-05-19 15:00 lst
drwxr-xr-x 3 root root  4096 2012-10-28 10:01 Synergy
drwxr-x--- 2 root root  4096 2011-03-10 20:54 tmp
drwxr-x--- 2 root root  4096 2011-03-10 20:54 www

What's happening here?

Answer 1

If I understand your setup correctly, /root/sbin on LX04 is a symbolic link to /usr/local/sbin. Therefore /0/LX04/root/sbin on LX02, which is part of an SSHFS filesystem, is a symbolic link to /usr/local/sbin. When you're on LX02, the directory /0/LX04/root/sbin is located at /usr/local/sbin, and that's the contents you're seeing. Since you're on LX02, you are of course seeing LX02's /usr/local/sbin (which is also accessible via /root/sbin).

Symbolic links are purely textual, they don't carry any information about the filesystem that you think they should be targetting.

If you want /0/LX04/root/sbin to point to the /usr/local/sbin from LX04, make it a symbolic to /0/LX04/usr/local/sbin. If you want /0/LX04/root/sbin to show /usr/local/sbin from the same machine that it's on (which here is the same thing), make it a relative link: /root/sbin ->../usr/local/sbin (run ln -snf ../usr/local/sbin /0/LX04/root/sbin. It's usually a good idea to make symbolic links relative, that more often than not gives the desired result when doing complex mounting.