The task:- to build a menu-driven image deployment front end for G4U.
Why? G4U provides tremendous functionality, but within a large IT department, the need to deploy images as rapidly as possible left me looking to improve on what was already available.
MIDS allows us to boot a machine using a MIDS CD, select which image server (FTP Server) we wish to download from, select the image from a list, hit GO and have the workstation booting it’s operating system just a 2 ½ minutes later.
Click to enlarge image
For impatient people, all you need to do is download the ISO and the support files and away you go. However, to get the most from MIDS, you’ll want to read on.
Why bother with MIDS?
Fast Image Deployment.
First Trick: Don’t try to restore the whole disk.
Suppose your IT department buys a bunch of machines with 80gb hard disks. You’ll setup a basic image (for arguments sake, lets assume it’s Windows XP) using the whole disk for C:. G4U will read the entire disk from beginning to end and store all those 1’s and 0’s in the GZ file. Even using the tools provided to keep the GZ file as small as possible, you’ll end up restoring 78gb of 0’s which takes time.
MIDS makes this fast by:
Creating the first small (2gb?) partition and setting it active.
Writing a Master Boot Record (MBR), so that it will boot the active partition
Restoring just the 2gb partition from a designated FTP server.
After this, XP will boot. So long as you include
ExtendOemPartition = 1
in your sysprep.inf file, mini-setup will expand the active partition to the entire disk (this process takes only a fraction of a second) and you have a 80gb XP workstation.
In these days of mice, many staff (even IT staff) are scared of a command prompt. By providing a menu-driven interface, folks are spared the need to type too much. This has benefits for speed also.
Control of images
Having used commercially available imaging tools for a number of years, I have learnt that
keeping on top of the versioning was a real headache. Engineers would take a CD-copy of
an image and trot off around the country with it. We would find machines even years later which
had a buggy image on them and wonder why.
Using a menu-driven approach means we KNOW which images are current and being installed on
workstations within the organisation. We no-longer have to duplicate a pile of CDs when a
new image comes out and hand it to each engineer. The engineers boot MIDS and select from
a list of images (which we manage) and install what we are happy with.
How does MIDS work?
MIDS is a slight modification to G4U. Instead of booting a memory-resident version of
NetBSD and the providing all the tools on the CD. MIDS downloads it’s menus and some
tools it requires (e.g. fdisk) from an FTP server.
It will download from the DNS name of MIDS therefore if your DHCP server hands out the domain of ‘company.com’ MIDS will look for ‘MIDS.company.com’.
From there it will connect and download /mids/1.0/autoexec.sh and execute it. This provides the administrator the way in to make the MIDS clients do what he or she wants.
In the example files provided, we display a ‘welcome’ page a ‘server selection’ page and
an ‘image selection’ page. You may, of course, customize these to suit your own needs.
Remember, this is still G4U underneath. How you use MIDS is entirely up to you, but it’s real power is in simplifying repetitive tasks. For me this means deploying images to workstations. You might have a different requirement, such as backup. If so, then simply modify the script to do what you require.