[Discuss] Ideas for solving a remove backup quandary

[Jeremy Kiffiak]

Ok, here is my attempt at trying to explain concisely what I am hoping  
to accomplish.

I have a computer at one location (lets call it LOCAL) from which I  
wish to back up certain data to a remote computer (lets call it  
REMOTE).  Now if that was all that it entailed I could quite easily  
and simply use rsync via ssh and would not need to compose this  
email.  However there are a few extra's twists.

REMOTE is running some virtualization software (VMWare Server 1.04)  
and the "system" I want to back up to is a VM (Virtual Machine)(lets  
call this VM REMOTE-BACKUP).  I realize that even this does not pose  
much of a problem with the proper port forwarding or perhaps SSH  
tunneling. REMOTE-BACKUP is itself behind a proxy/firewall/gateway VM  
(REMOTE-GW).

REMOTE-GW has multiple virtual NIC's to provide each of the other VM's  
its own private network addressing space (yes I could do something via  
netmask) with the following IP setup for all mentioned systems and VM's.

LOCAL = 192.168.10.100
REMOTE = 192.168.18.254
REMOTE-GW(IP1) = 192.168.18.100
REMOTE-GW(IP2) = 10.10.8.1
REMOTE-BACKUP = 10.10.8.128

I have been fumbling my way through making a BASH script to help  
automate the process.  The script I have previously used (when the  
remote BACKUP system was directly accessible via SSH) was this:

#!/bin/sh
rsync --archive --delete --verbose --compress --rsh=ssh \
/home/<username>/<dir_to_backup>/  \
<username>@:/home/jmkiffiak/mysql_backups/  \
/home/<username>/logs/ >> rsync.log

I would like to do something similar with the new backup system as  
well.  I thought to include an SSH tunnel at the beginning of my  
script but the script hangs on that line.  The new (borked) script  
follows.  I have added a few "echo" commands to try and see where the  
script was hanging.  I am using port 10022 for 2 reasons.  First it is  
non-standard so hopefully less script-kiddy port scans will find it.   
Second I have multiple boxes running SSH on the REMOTE network.  On  
the remote router port 10022 forwards to port 22 on REMOTE-GW(IP1).

#!/bin/sh
echo "Creating remote tunnel . . ."
ssh -p 10022 -C -N <username>@REMOTE1	\
	-L localhost:18128:10.10.8.128:22 &&
echo "Tunnel created successfully!"
echo "Starting backup process"
scp -p -P 18128 <username>@localhost:~/
echo "File(s) backed up!"

How can I create a BASH script that initially creates an SSH tunnel  
that rsync or scp can use to access the machine behind the gateway VM?

Jeremy

ps:  And if you understand all of that very much non-concise mess give  
yourself a high-five or pat on the head or a shot of your favorite  
drink as a reward.  As for me it's time for a nap.  My brain hurts.