RE: [SAGE] JAILS (Re: Respondents needed for article on sysadmin survival)

["Dustin Puryear" <dpuryear@usa.net>]

> On Fri, Jan 16, 2004 at 12:07:06PM -0600, Dustin Puryear wrote:
> > ...
> > It's the same idea as VMware. You build a virtual machine and move it
> around
> > as needed instead of building "the machine".
> 
> ???
> 
> you still have to essentially build out duplicate a "new" copy of the OS
> to run inside the virtual machine, one way or another.
> You only "save" on hardware setup.

True and false.

# mkdir /jails/mail.example.com
# cd /jails/mail.example.com
# tar xzf /jails/skel.tgz
# /jails/bin/install-mail.sh /jails/mail.example.com
# jail /jails/mail.example.com ...

I'm done.

With those five lines I can bring up fifty or five hundred new virtual
servers without ever modifying the base system, hitting the power button, or
even notifying clients that a change to the system is being made.

Again, let me agree with everyone about to hit the Reply button that with
*proper scripting and/or management procedures I can easily ramp up a new
server*. No problem. 

But can it be done even better?

With virtual servers (however implemented) I can usually bring a "server" up
a lot faster (as opposed to a system--the hardware/OS), and I can run
several services/servers on the same piece of hardware even though each
service may normally interfere with one another (i.e., if each service
required a difference version of a system library or something, say if for
example one package wants mysql323-server while another wants
mysql40-server).

Keep in mind that I am not arguing for FreeBSD jails here. I am just using
FreeBSD jails as an easy example of what I'm talking about.

---
Dustin Puryear
Puryear Information Technology, LLC
Baton Rouge, LA
http://www.puryear-it.com