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

Tunnelblick 3.6.7beta02 - GUI for OpenVP...
Tunnelblick is a free, open source graphic user interface for OpenVPN on OS X. It provides easy control of OpenVPN client and/or server connections. It comes as a ready-to-use application with all... Read more
jAlbum Pro 13.4 - Organize your digital...
jAlbum Pro has all the features you love in jAlbum, but comes with a commercial license. You can create gorgeous custom photo galleries for the Web without writing a line of code! Beginner-friendly... Read more
calibre 2.65.1 - Complete e-book library...
Calibre is a complete e-book library manager. Organize your collection, convert your books to multiple formats, and sync with all of your devices. Let Calibre be your multi-tasking digital librarian... Read more
jAlbum 13.4 - Create custom photo galler...
With jAlbum, you can create gorgeous custom photo galleries for the Web without writing a line of code! Beginner-friendly, with pro results - Simply drag and drop photos into groups, choose a design... Read more
Backblaze 4.2.0.966 - Online backup serv...
Backblaze is an online backup service designed from the ground-up for the Mac. With unlimited storage available for $5 per month, as well as a free 15-day trial, peace of mind is within reach with... Read more
Backblaze 4.2.0.966 - Online backup serv...
Backblaze is an online backup service designed from the ground-up for the Mac. With unlimited storage available for $5 per month, as well as a free 15-day trial, peace of mind is within reach with... Read more
Tunnelblick 3.6.7beta02 - GUI for OpenVP...
Tunnelblick is a free, open source graphic user interface for OpenVPN on OS X. It provides easy control of OpenVPN client and/or server connections. It comes as a ready-to-use application with all... Read more
calibre 2.65.1 - Complete e-book library...
Calibre is a complete e-book library manager. Organize your collection, convert your books to multiple formats, and sync with all of your devices. Let Calibre be your multi-tasking digital librarian... Read more
jAlbum Pro 13.4 - Organize your digital...
jAlbum Pro has all the features you love in jAlbum, but comes with a commercial license. You can create gorgeous custom photo galleries for the Web without writing a line of code! Beginner-friendly... Read more
jAlbum 13.4 - Create custom photo galler...
With jAlbum, you can create gorgeous custom photo galleries for the Web without writing a line of code! Beginner-friendly, with pro results - Simply drag and drop photos into groups, choose a design... Read more

Clean Text (Productivity)
Clean Text 1.0 Device: iOS Universal Category: Productivity Price: $3.99, Version: 1.0 (iTunes) Description: | Read more »
Gemini - A Journey of Two Stars (Games)
Gemini - A Journey of Two Stars 1.0.1 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0.1 (iTunes) Description: *** SPECIAL LAUNCH SALE: $2.99 (25% off) *** "A mesmerizing and unexpectedly emotional journey." -- Los... | Read more »
How to get four NFL superstars for your...
Even though you're probably well on your way to building a top notch squad for the new season in Madden NFL Mobile, let's say you could beef it up by adding Rob Gronkowski, Antonio Brown, Von Miller, and Todd Gurley to your roster. That's... | Read more »
Cartoon Network Superstar Soccer: Goal!!...
Cartoon Network Superstar Soccer: Goal!!! – Multiplayer Sports Game Starring Your Favorite Characters 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Become a soccer superstar with your... | Read more »
NFL Huddle: What's new in Topps NFL...
Can you smell that? It's the scent of pigskin in the air, which either means that cliches be damned, pigs are flying in your neck of the woods, or the new NFL season is right around the corner. [Read more] | Read more »
FarmVille: Tropic Escape tips, tricks, a...
Maybe farming is passé in mobile games now. Ah, but farming -- and doing a lot of a other things too -- in an island paradise might be a little different. At least you can work on your tan and sip some pina coladas while tending to your crops. [... | Read more »
Become the King of Avalon in FunPlus’ la...
King Arthur is dead. Considering the legend dates back to the 5th century, it would be surprising if he wasn’t. But in the context of real-time MMO game King of Avalon: Dragon Warfare, Arthur’s death plunges the kingdom into chaos. Evil sorceress... | Read more »
Nightgate (Games)
Nightgate 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: *** Launch Sale: 25% OFF for a limited time! *** In the year 2398, after a great war, a network of intelligent computers known as... | Read more »
3 best fantasy football apps to get you...
Last season didn't go the way you wanted it to in fantasy football. You were super happy following your drafts or auctions, convinced you had outsmarted everyone. You were all set to hustle on the waiver wire, work out some sweet trades, and make... | Read more »
Pokemon GO update: Take me to your leade...
The Team Leaders in Pokemon GO have had it pretty easy up until now. They show up when players reach level 5, make their cases for joining their respective teams, and that's pretty much it. Light work, as Floyd Mayweather might say. [Read more] | Read more »

Price Scanner via MacPrices.net

Global Tablet Shipments Projected to Increase...
Digitimes’ Jim Hsiao reports that global tablet shipments will increase by 16.3 percent sequentially to reach nearly 47 million units in 2016′s third quarter, but that volume will still be down over... Read more
Apple’s 2016 Back to School promotion: Free B...
Purchase a new Mac or iPad using Apple’s Education Store and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free, and... Read more
Apple refurbished iPad Air 2s available start...
Apple has Certified Refurbished iPad Air 2 available starting at $339. Apple’s one-year warranty is included with each model, and shipping is free: - 128GB Wi-Fi iPad Air 2: $499 - 64GB Wi-Fi iPad... Read more
13-inch 2.5GHz MacBook Pro available for $961...
Overstock has the 13″ 2.5GHz MacBook Pro available for $961.63 including free shipping. Their price is $138 off MSRP. Read more
Clearance 12-inch Retina MacBooks, Apple refu...
Apple has Certified Refurbished 2015 12″ Retina MacBooks available starting at $929. Apple will include a standard one-year warranty with each MacBook, and shipping is free. The following... Read more
BookBook Releases SurfacePad, BookBook &...
BookBook has released three new covers just for iPad Pro: SurfacePad, BookBook and BookBook Rutledge Edition. BookBook for iPad Pro is a gorgeous leather case reminiscent of a vintage sketchbook.... Read more
Clean Text 1.0 for iOS Reduces Text Cleanup a...
Apimac today announced availability of Clean Text for iOS, a tool for webmasters, graphic designers, developers and magazine editors to reduce text cleanup and editing time, and also for any iPhone... Read more
27-inch iMacs on sale for up to $220 off MSRP
B&H Photo has 27″ Apple iMacs on sale for up to $200 off MSRP including free shipping plus NY sales tax only: - 27″ 3.3GHz iMac 5K: $2099 $200 off MSRP - 27″ 3.2GHz/1TB Fusion iMac 5K: $1899 $100... Read more
Apple refurbished 13-inch MacBook Airs availa...
Apple has Certified Refurbished 2016 and 2015 13″ MacBook Airs now available starting at $849. An Apple one-year warranty is included with each MacBook, and shipping is free: - 2016 13″ 1.6GHz/8GB/... Read more
Apple refurbished iPad mini 2s available for...
Apple is offering Certified Refurbished iPad mini 2s for up to $80 off the cost of new minis. An Apple one-year warranty is included with each model, and shipping is free: - 16GB iPad mini 2 WiFi: $... Read more

Jobs Board

*Apple* Solutions Consultant - Apple (United...
Apple Solutions ConsultantJob Number: 51218534Pleasant Hill, California, United StatesPosted: Aug. 18, 2016Weekly Hours: 40.00Job SummaryAs an Apple Solutions Read more
SW Engineer *Apple* TV - Apple Inc. (United...
The Apple TV team is looking for excellent software engineers with experience in hardware, media management, media playback, content delivery and a passion for Read more
*Apple* Retail - Multiple Positions (US) - A...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Seasonal Sales Associate - *Apple* Blossom...
Seasonal Sales Associate - Apple Blossom Mall Location:Winchester, VA, United States- Apple Blossom Mall 1850 Apple Blossom Dr Job ID:1001993 Date:August 22, Read more
*Apple* Engineer - Softthink Solutions, Inc....
Job Description:- Proven experience in administering IOS and OSX Apple devices in enterprises - Experience in administering Apple devices in Windows environments Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.