Moving Data from Linux to the Mac

Making the move to a new operating system is a daunting task. You have to learn a new graphical interface, new programs, and also have to find a way to preserve your precious data. Having made a successful transition from Linux to Mac, here are a few tips for those considering the jump.

Staying Neutral in the Format Wars

Over the last ten years, I've gone from being a Windows desktop user to a Linux desktop user to a Mac desktop user. My core data has traveled with me every step of the way. This includes text files, images, office documents, PDFs, Palm data files, audio, video, Java packages, and more. Since it's impossible to know the future with certainty, I strive to keep my data in neutral, cross-platform formats.

In some cases, program or platform-specific file formats are unavoidable. If you work at it, you can keep important data in a format that can easily be moved from one system to another. My first suggestion is to get your data into portable, open formats.

Nothing is more portable than plain text. Plain text is not sexy or flashy, but it is durable. Standardized image formats (GIF, JPEG, PNG) are also completely portable. Cross platform application file formats, like Gimp, are also portable. If you are Palm PDA user, you'll find that Palm files and synchronization work flawlessly on the Mac.

Though complaints were lodged against Leopard, since it shipped without the latest version of Java, I've had no problems running Java desktop applications. In fact, OS X has a program (installed with the development tools) that lets you bundle a Java app to make it look like a native Mac app.

Audio and video formats are discussed in a more detail below.

File Names and Line Endings

With current versions of OS X, Linux, and Windows, long file names are portable and not much of a concern. Windows doesn't honor capitalization, but when moving from Linux to Mac, that is not a problem. I delved into the nuances of file names elsewhere.

Both Linux and OS X use a single carriage return character (ASCII code 13) to mark the end of a line in a text file. Windows uses the two characters, carriage return and line feed (ASCII code 10). Some text editors (including nano) can automatically convert text line endings, and there are utility programs that convert both ways (unix2dos and dos2unix). Both utilities are available through MacPorts.

Audio Files, iTunes, and the iPod

For compressed audio files, I recommend MP3 format. If you are concerned about the licensing issues surrounding MP3, Ogg Vorbis is available. While Ogg Vorbis is patent free, cost free, and DRM free, it currently doesn't work on the iPod. There is a plugin for iTunes to play Ogg Vorbis files, but if you want to take advantage of iTunes/iPod synergy, stick to MP3. iTunes also has the native ability to rip CDs directly to MP3. MP3s are fully licensed on OS X, so there are no intellectual property issues. Down the road, if you want to move to another OS, MP3s will be still be the easiest to transfer.

One more tip concerning iTunes: When you import music files into the iTunes library, it does more than index the file, it physically copies it to /Users/username/Music/iTunes/iTunes Music/artist/. So, after you import music files into iTunes, there are two copies of each audio file imported into iTunes. You can choose to maintain separate copies or let iTunes manage your files.

Video Files

I don't have a large video collection, but I have had good luck playing MPEG files on all platforms. Like MP3, it seems to be ubiquitous. OS X favors QuickTime files (.mov) but comes with many other codecs.

Finder Droppings

The Finder is the default file manager in OS X. Coming from Linux, I spent a lot of quality time on the command line. I still do on OS X and was somewhat dismayed to find hidden files in every directory touched by the Finder.

In every directory browsed by the Finder, it creates a .DS_Store file (Desktop Services Store). The .DS_Store contains the Finder viewing preferences for that directory. At the root of every Volume that the Finder touches, it creates a .Trashes directory to store deleted files. There is no way to turn of .DS_Store droppings on locally connected drives, but you can change a Finder default to prevent it from creating .DS_Store files on network drives. Run this command in the Terminal to turn off .DS_Store creation on network drives:

defaults write com.apple.desktopservices DSDontWriteNetworkStores true

It's All About the Bits

Your data is arguably more important than the platform or operating system you use. It is certainly more difficult to replace. Aiming for platform neutral data formats allows you maximum flexibility moving from Linux to Mac. It also makes it easier for you to share your data with people who use different systems.