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.

 
AAPL
$119.00
Apple Inc.
+1.40
MSFT
$47.75
Microsoft Corpora
+0.28
GOOG
$540.37
Google Inc.
-0.71

MacTech Search:
Community Search:

Software Updates via MacUpdate

Skype 7.2.0.412 - Voice-over-internet ph...
Skype allows you to talk to friends, family and co-workers across the Internet without the inconvenience of long distance telephone charges. Using peer-to-peer data transmission technology, Skype... Read more
HoudahSpot 3.9.6 - Advanced file search...
HoudahSpot is a powerful file search tool built upon MacOS X Spotlight. Spotlight unleashed Create detailed queries to locate the exact file you need Narrow down searches. Zero in on files Save... Read more
RapidWeaver 6.0.3 - Create template-base...
RapidWeaver is a next-generation Web design application to help you easily create professional-looking Web sites in minutes. No knowledge of complex code is required, RapidWeaver will take care of... Read more
iPhoto Library Manager 4.1.10 - Manage m...
iPhoto Library Manager lets you organize your photos into multiple iPhoto libraries. Separate your high school and college photos from your latest summer vacation pictures. Or keep some photo... Read more
iExplorer 3.5.1.9 - View and transfer al...
iExplorer is an iPhone browser for Mac lets you view the files on your iOS device. By using a drag and drop interface, you can quickly copy files and folders between your Mac and your iPhone or... Read more
MacUpdate Desktop 6.0.3 - Discover and i...
MacUpdate Desktop 6 brings seamless 1-click installs and version updates to your Mac. With a free MacUpdate account and MacUpdate Desktop 6, Mac users can now install almost any Mac app on macupdate.... Read more
SteerMouse 4.2.2 - Powerful third-party...
SteerMouse is an advanced driver for USB and Bluetooth mice. It also supports Apple Mighty Mouse very well. SteerMouse can assign various functions to buttons that Apple's software does not allow,... Read more
iMazing 1.1 - Complete iOS device manage...
iMazing (was DiskAid) is the ultimate iOS device manager with capabilities far beyond what iTunes offers. With iMazing and your iOS device (iPhone, iPad, or iPod), you can: Copy music to and from... Read more
PopChar X 7.0 - Floating window shows av...
PopChar X helps you get the most out of your font collection. With its crystal-clear interface, PopChar X provides a frustration-free way to access any font's special characters. Expanded... Read more
OneNote 15.4 - Free digital notebook fro...
OneNote is your very own digital notebook. With OneNote, you can capture that flash of genius, that moment of inspiration, or that list of errands that's too important to forget. Whether you're at... Read more

Latest Forum Discussions

See All

Lucha Amigos (Games)
Lucha Amigos 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Forget Ninja Turtles, and meet Wrestlers Turtles! Crazier, Spicier and…Bouncier! Sling carapaces of 7 Luchadores to knock all... | Read more »
Raby (Games)
Raby 1.0.3 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0.3 (iTunes) Description: ***WARNING - Raby runs on: iPhone 5, iPhone 5C, iPhone 5S, iPhone 6, iPhone 6 Plus, iPad Mini Retina, iPad Mini 3, iPad 4, iPad Air,... | Read more »
Oddworld: Stranger's Wrath (Games)
Oddworld: Stranger's Wrath 1.0 Device: iOS Universal Category: Games Price: $5.99, Version: 1.0 (iTunes) Description: ** PLEASE NOTE: Oddworld Stranger's Wrath requires at least an iPhone 4S, iPad 2, iPad Mini or iPod Touch 5th gen... | Read more »
Bounce On Back (Games)
Bounce On Back 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: | Read more »
Dwelp (Games)
Dwelp 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: === 50% off for a limited time, to celebrate release === Dwelp is an elegant little puzzler with a brand new game mechanic. To complete a... | Read more »
Make Way for Fat Chicken, from the Maker...
Make Way for Fat Chicken, from the Makers of Scrap Squad Posted by Jessica Fisher on November 26th, 2014 [ permalink ] Relevant Games has announced they will be releasing their reverse tower defense game, | Read more »
Tripnary Review
Tripnary Review By Jennifer Allen on November 26th, 2014 Our Rating: :: TRAVEL BUCKET LISTiPhone App - Designed for the iPhone, compatible with the iPad Want to create a travel bucket list? Tripnary is a fun way to do exactly that... | Read more »
Ossian Studios’ RPG, The Shadow Sun, is...
Ossian Studios’ RPG, The Shadow Sun, is Now Available for $4.99 Posted by Jessica Fisher on November 26th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Mmmm, Tasty – Having the Angry Birds for...
The very first Angry Birds debuted on iOS back in 2009. When you sit back and tally up the number of Angry Birds games out there and the impact they’ve had on pop culture as a whole, you just need to ask yourself: “How would the birds taste... | Read more »
Rescue Quest Review
Rescue Quest Review By Jennifer Allen on November 26th, 2014 Our Rating: :: PATH BASED MATCH-3Universal App - Designed for iPhone and iPad Guide a wizard to safety by matching gems. Rescue Quest might not be an entirely original... | Read more »

Price Scanner via MacPrices.net

Apple Store Black Friday sale for 2014: $100...
BLACK FRIDAY The Apple Store has posted their Black Friday deals for 2014. Receive a $100 PRODUCT(RED) branded iTunes gift card with the purchase of select Macs, $50 with iPads, and $25 with iPods,... Read more
Black Friday: 15% off iTunes Gift Cards
Staples is offering 15% off $50 and $100 iTunes Gift Cards on their online store as part of their Black Friday sale. Click here for more information. Shipping is free. Best Buy is offering $100... Read more
BEVL Releases Dock Tailored for iPhone 6 and...
Seattle based BEVL has released their first product: an iPhone dock that is divergent in build quality, rock-solid function and visual simplicity to complement the iPhone. BEVL is now accepting... Read more
Black Friday: $150 off 13-inch Retina MacBook...
 Best Buy has 13-inch 2.6GHz Retina MacBook Pros on sale for $150 off MSRP on their online store as part of their Black Friday sale. Choose free shipping or free local store pickup (if available).... Read more
Black Friday: $300 off 15-inch Retina MacBook...
 B&H Photo has the new 2014 15″ Retina MacBook Pros on sale for $300 off MSRP as part of their Black Friday sale. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.2GHz Retina... Read more
Black Friday: Up to $140 off MacBook Airs, fr...
 B&H Photo has 2014 MacBook Airs on sale for up to $140 off MSRP as part of their Black Friday sale. Shipping is free, and B&H charges NY sales tax only: - 11″ 128GB MacBook Air: $799 $100... Read more
Black Friday: 13-inch 2.5GHz MacBook Pro on s...
 Best Buy has the 13″ 2.5GHz MacBook Pro on sale for $899.99 on their online store as part of their Black Friday sale. Choose free shipping or free instant local store pickup (if available). Their... Read more
Black Friday: 21-inch 1.4GHz iMac on sale for...
 Best Buy has the 21″ 1.4GHz iMac on sale for $899.99 on their online store as part of their Black Friday sale. Their price is $200 off MSRP. Choose free shipping or free local store pick up. Price... Read more
Black Friday iPad Air 2 sale prices, $100 off...
 Best Buy has iPad Air 2s on sale for $100 off MSRP on their online store for Black Friday. Choose free shipping or free local store pickup (if available). Sale prices available for online orders... Read more
2014 1.4GHz Mac mini on sale for $449, save $...
 B&H Photo has the new 1.4GHz Mac mini on sale for $449.99 including free shipping plus NY tax only. Their price is $50 off MSRP, and it’s the lowest price available for this new model. Adorama... Read more

Jobs Board

*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
Senior Event Manager, *Apple* Retail Market...
…This senior level position is responsible for leading and imagining the Apple Retail Team's global event strategy. Delivering an overarching brand story; in-store, Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.