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Thanks and suggestions


Many thanks for producing ezjail. We use Jails at Swinburne University
to provide virtual hosts to students to help teach Unix skills. We
usually deploy upwards of 200 jails on a single server host with much

We traditionally developed our own management tools
(http://caia.swin.edu.au/rule) however this was a binary solution and
ran on FreeBSD 5.3. Following a recent upgrade without time to port our
solution to BSD 8.0, we decided to try ezjail and have been very
impressed. Many thanks for your work and input.

Please find below a handful of either minor bugs or suggestions for
further improvements.

1) Use of rc.conf _interface variables.

Individual jail config variables are stored in
/usr/local/etc/ezjail/jail_name. The current /etc/rc.d/jail script
supports the "jail_(jailname)_interface" variable. If this variable is
defined then the following commands are run on jail startup (ifconfig
_interface alias _ip) and shutdown (ifconfig _interface -alias _ip).

This allows us to not worry about configuring all 100+ IP addresses in
rc.conf. I tested by adding a jail_name_interface variable with the
interface name to the /usr/local/etc/ezjail files and found that it all
worked properly. I suggest an extra parameter to "ezjail-admin create"
to optionally specify the interface name and if provided to write this
variable to the jail config file.

2) Support for FIB tables

BSD now supports multiple routing tables. Jails are automatically
started using the correct routing table by /etc/rc.d/jail if the
corresponding jail_(jailname)_fib variable is defined.  As per
suggestion 1 above, it would be cool if ezjail-admin allowed optional
specification of the fib value to use and to store in the corresponding
jail config file.

This would also require changes to "ezjail-admin console" to launch
jexec with the corresponding routing table

exec setfib ${jail_fib} jexec ${ezjail_id} ${ezjail_default_execute}

Please note that FIB support is not yet perfect on BSD yet and while
alot of stuff worked, some didn't. For this feature I am thinking more
of the future when they do work properly

3) Support for sparse image files

To save space (with hundreds of jails), we used to use sparse image
files as our disk images. These files grew as students installed files
in their jails. It would be extremely nice if the "exjail-admin create"
provided support for sparse file images as well.

Again, thanks for your efforts, ezjail has certainly lightened our
workload as we migrate to using BSD 8. I hope that my suggestions above
are considered useful



Dr. Jason But
Centre for Advanced Internet Architectures
Faculty of Information and Communication Technologies
Swinburne University of Technology

Phone: +61 3 9214 4839
Email: jbut AT swin.edu DOT au
www:   http://caia.swin.edu.au