TweetFollow Us on Twitter

MacEnterprise: "Image"ine That!

Volume Number: 24 (2008)
Issue Number: 03
Column Tag: MacEnterprise

MacEnterprise: "Image"ine That!

A fresh look at creating deployment images

By Philip Rinehart, Yale University

Images?

In the System Imaging and Deployment Power Tools session at Macworld this year, there was a large amount of time spent discussing system imaging. How does it work? What are best practices? Are there best practices? How do you deal with new hardware, and more were asked. I thought it would be useful this month to reexamine the practice of image creation. Let's start by looking at what we mean by an image.

The "Image"

In traditional Macintosh system administration, an image is a base operating system plus some amount of software that is applied to one or more machines. In general, the nirvana has been to create a single image that can be applied to many different models of Mac machines. Is this goal achievable, or is it like Buddhism, in which the journey is more important?

Rule 1: currency

The first rule of system imaging is that an image must be created from the most current model of Macintosh in any deployment. Typically this image is created from the installation media that was shipped with the hardware. For example, if your deployment includes a quad core Intel machine, then create the image from that disc. Is this rule inviolable? No.

How do you update an existing image? Wait until the dot release update. That is, if your image was created on 10.4.10, update your image for new hardware at 10.4.11. There is some debate about using a combo updater or a delta. Generally, I prefer to use the combo updater, as each and every update from the Gold Master is applied. This method can be used to update existing images pretty reliably. There are of course exceptions, but now that a universal operating system is available, Leopard, this method should work in most cases.

Rule 2: User templates

The second rule of thumb in system imaging is how to create a default template. Note that this method applies to local accounts, not network accounts. First, create a template user using system preferences. Next, login as that user, and run each application that it is important to configure. Common configuration items include web browsers, word processing applications, or site-specific applications that need consistent settings. There are a couple of gotchas though.

First, for the template user, don't store anything in the keychain. When the template is copied over any item stored in the keychain will be inaccessible to the new account. It is safe to delete the keychain after finishing custom configuration as well. Secondly, be certain to set the proper downloads folder for each web browser. In Tiger, if the Safari download folder were not set, a copied template would contain an inaccessible path. The last gotcha is for any preferences that are machine specific. This type of preference is usually stored in ~/Library/Preferences/ByHost. Common items here include iTunes preferences, screensaver preferences, and others. A hardware address is embedded in the preference file name. It can be corrected with a loginhook.

Rule 3: Cleanup

Before applying any image, it is important to do some basic cleanup. What should be cleaned up though? There are a few obvious things to remove for initial cleanup. Get rid of any Cache files stored in /Library/Caches, and /System/Library/Caches. Next, remove both swap files and sleep images. These are located in the directory /var/vm, and can be significant in size. One other cache can also be removed, the BootCache.playlist located in /private/var/db.

What about other types of files? Generally, I would recommend moving the Network Interfaces plist in /Library/Preferences/SystemConfiguration. In general, these files are machine specific, and will get recreated by the operating system on first boot. This also removes any possible conflict if an image has a different network interface configuration then its target.

System wide, these files are ignored by Time Machine, and can probably be eliminated from any image.

                      /.Spotlight-V100
                /.Trashes
                /.fseventsd
                /.hotfiles.btree
                /Backups.backupdb
                /Desktop DB
                /Desktop DF
                /Network/Servers
                /Previous Systems
                /Users/Shared/SC Info
                /Users/Guest
                /dev
                /home
                /net
                /private/var/db/Spotlight
                /private/var/db/Spotlight-V100

Note that most of these files are fairly logical to be excluded. The operating system will recreate any of these files at first boot.

Clean up of the User Template can also be a little more complete as well. Here are the files that can be excluded from the User Template. Most are related to browsers and rss feeds.

                    Library/Application Support/MobileSync
                Library/Application Support/SyncServices
                Library/Caches
                Library/Logs
                Library/Mail/Envelope Index
                Library/Mail/AvailableFeeds
                Library/Mirrors
                Library/PubSub/Database
                Library/PubSub/Downloads
                Library/PubSub/Feeds
                Library/Safari/Icons.db
                Library/Safari/HistoryIndex.sk

The last thing to eliminate is any Log files, both in /Library/Logs and /private/var/log. No need to have any of these items on an image! Note that the cleanup process is best scripted, as no one really wants to remember all of these steps!

Apple software restore

Now that you have created your "perfect" image, it is time to get it ready for deployment. Are there best practices here? I think so. First, it is best to boot from an alternate volume. This volume can be a separate partition, or an external drive. Once booted the steps are pretty straightforward.

1. Open Disk Utility

2. Select the drive or partition that is the model for imaging

3. Select "Image from Folder" and select the hard drive and wait. A long time.

4. Select "Scan Image for Restore" and scan the newly created dmg file.

That's it! You then have an image that is ready for deployment via whatever method you have in place to put an image on a machine via multicast ASR, NetRestore, or any other method you have of getting the image on the machine. One important note though, it is generally best to have at least twice the amount of space needed to create an image on your external drive. If your drive has any less than that, the imaging operation may fail.

The future

The method I have just described is the "Classic" way of creating methods and is fairly tried and true. However, it isn't really very scalable, or flexible as the image is a point in time snapshot. The way of the future can be seen in two areas, the new System Imaging Utility in Leopard and InstaDMG from afp548.com. Both take the idea of monolithic image creation, and move it to a more modular approach. Ultimately this approach is far more flexible, allowing updating any image at a moments notice. It also makes it easier to be extremely flexible and adaptable, which is a good thing in today's fast moving environments. It was good to see all at Macworld this year, until next month see you on the lists!


Philip Rinehart is co-chair of the steering committee leading the Mac OS X Enterprise Project (macenterprise.org) and is the Lead Mac Analyst at Yale University. He has been using Macintosh Computers since the days of the Macintosh SE, and Mac OS X since its Developer Preview Release. Before coming to Yale, he worked as a Unix system administrator for a dot-com company. He can be reached at: philip.rinehart@yale.edu. The MacEnterprise project is a community of IT professionals sharing information and solutions to support Macs in an enterprise. We collaborate on the deployment, management, and integration of Mac OS X client and server computers into multi-platform computing environments.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

BBEdit 11.6.4 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more
BBEdit 11.6.4 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more
beaTunes 4.6.12 - Organize your music co...
beaTunes is a full-featured music player and organizational tool for music collections. How well organized is your music Library? Are your artists always spelled the same way? Any R.E.M. vs REM?... Read more
Tinderbox 7.0.1 - Store and organize you...
Tinderbox is a personal content management assistant. It stores your notes, ideas, and plans. It can help you organize and understand them. And Tinderbox helps you share ideas through Web journals... Read more
FotoMagico 5.4 - Powerful slideshow crea...
FotoMagico lets you create professional slideshows from your photos and music with just a few, simple mouse clicks. It sports a very clean and intuitive yet powerful user interface. High image... Read more
Direct Mail 4.3.9 - Create and send grea...
Direct Mail is an easy-to-use, fully-featured email marketing app purpose-built for OS X. It lets you create and send great looking email campaigns. Start your newsletter by selecting from a gallery... Read more
Tinderbox 7.0.1 - Store and organize you...
Tinderbox is a personal content management assistant. It stores your notes, ideas, and plans. It can help you organize and understand them. And Tinderbox helps you share ideas through Web journals... Read more
Direct Mail 4.3.9 - Create and send grea...
Direct Mail is an easy-to-use, fully-featured email marketing app purpose-built for OS X. It lets you create and send great looking email campaigns. Start your newsletter by selecting from a gallery... Read more
FotoMagico 5.4 - Powerful slideshow crea...
FotoMagico lets you create professional slideshows from your photos and music with just a few, simple mouse clicks. It sports a very clean and intuitive yet powerful user interface. High image... Read more
beaTunes 4.6.12 - Organize your music co...
beaTunes is a full-featured music player and organizational tool for music collections. How well organized is your music Library? Are your artists always spelled the same way? Any R.E.M. vs REM?... Read more

The best sales on the App Store this wee...
The App Store has quite an exciting lineup of discount games this week that range across a variety of genres. It's a great opportunity to catch up on some of the premium games you may have been holding off on -- and some you can even grab for free... | Read more »
The best new games we played this week
Ah, here we are again at the close of another busy week. Don't rest too easy, though. We had a lot of great new releases in mobile games this week, and now you're going to have to spend all weekend playing them. That shouldn't be too much of a... | Read more »
Rollercoaster Tycoon Touch Guide: How to...
| Read more »
Rabbids Crazy Rush Guide: How to unlock...
The Rabbids are back in a new endless running adventure, Rabbids Crazy Rush. It's more ridiculous cartoon craziness as you help the little furballs gather enough fuel (soda) to get to the moon. Sure, it's a silly idea, but everyone has dreams --... | Read more »
Tavern Guardians (Games)
Tavern Guardians 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Tavern Guardians is a Hack-and-Slash action game played in the style of a match-three. You can experience high pace action... | Read more »
Slay your way to glory in idle RPG Endle...
It’s a golden age for idle games on the mobile market, and those addictive little clickers have a new best friend. South Korean developer Ekkorr released Endless Frontier last year, and players have been idling away the hours in the company of its... | Read more »
Tiny Striker: World Football Guide - How...
| Read more »
Good news everyone! Futurama: Worlds of...
Futurama is finding a new home on mobile in TinyCo and Fox Interactive's new game, Futurama: Worlds of Tomorrow. They're really doing it up, bringing on board Futurama creator Matt Groening along with the original cast and writers. TinyCo wants... | Read more »
MUL.MASH.TAB.BA.GAL.GAL (Games)
MUL.MASH.TAB.BA.GAL.GAL 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: ENDLESS UPGRADES. CONSTANT DANGER. ANCIENT WISDOM. BOUNCY BALLS. Launch Sale, 40% OFF for a very limited time!!! MUL.... | Read more »
Dungeon Rushers (Games)
Dungeon Rushers 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Dungeon Rushers is a 2D tactical RPG combining dungeon crawler’s gameplay and turn based fights. Manage your team, loot dusty... | Read more »

Price Scanner via MacPrices.net

13-inch 2.0GHz Apple MacBook Pros on sale for...
B&H has the non-Touch Bar 13″ 2.0GHz MacBook Pros in stock today and on sale for $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.0GHz MacBook Pro Space Gray (... Read more
15-inch Touch Bar MacBook Pros on sale for up...
B&H Photo has the new 2016 15″ Apple Touch Bar MacBook Pros in stock today and on sale for up to $150 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.7GHz Touch Bar... Read more
12-inch Retina MacBooks on sale for $1150, $1...
B&H has 12″ 1.1GHz Retina MacBooks on sale for $150 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 12″ 1.1GHz Space Gray Retina MacBook: $1149 $150 off MSRP - 12″ 1.1GHz... Read more
Apple restocks refurbished 11-inch MacBook Ai...
Apple has Certified Refurbished 11″ MacBook Airs (the latest models recently discontinued by Apple), available for up to $170 off original MSRP. An Apple one-year warranty is included with each... Read more
Apple Park Opens to Employees in April With T...
Apple has announced that Apple Park, the company’s new 175-acre campus, will be ready for employees to begin occupying in April. The process of moving more than 12,000 people will take over six... Read more
Manhattan Neighbors for Safer Telecommunicati...
A new education and advocacy group focused on cell phone and wireless risks, Manhattan Neighbors for Safer Telecommunications, launched today at http://www.ManhattanNeighbors.org. Manhattan... Read more
Portable Dual DisplayPort Monitor Dock Enable...
IOGEAR has announced the launch of its USB-C Dual DisplayPort Monitor Portable Dock (GUC3CMST). The dock enables users to easily connect two DisplayPort monitors to a USB-C or Thunderbolt 3 laptop to... Read more
13-inch 2.7GHz Retina MacBook Pro on sale for...
Amazon.com has restocked the 13″ 2.7GHz/128GB Retina MacBook Pro (MF839LL/A) for $200 off MSRP including free shipping: - 13″ 2.7GHz/128GB Retina MacBook Pro: $1099 $200 off MSRP This model tends to... Read more
Apple’s New iPad Ads Don’t Address Pro Users’...
Apple launched a new tranche of iPad Pro TV ads last week addressing actual queries and challenges from the Twitterverse, albeit using actors for the visuals. That’s great. As an iPad fan and heavy... Read more
Free Verbum Catholic Bible Study App For iOS
The Verbum mobile app runs on Logos’ powerful Bible software and is an advanced resource for mobile Catholic study. The Verbum app surrounds the Bible with the Tradition. Verbum comes with 15 free... Read more

Jobs Board

*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions- Chicago...
SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
Manager *Apple* Systems Administration - Pu...
Req ID 3315BR Position Title Manager, Apple Systems Administration Job Description The Manager of Apple Systems Administration oversees the administration and Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Manager *Apple* Systems Administration - Pu...
Req ID 3315BR Position Title Manager, Apple Systems Administration Job Description The Manager of Apple Systems Administration oversees the administration and Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.