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Wasted gigabytes

No matter how large is your hard disk, sooner or later you’ll run out of space. Gigabytes of movies, music, ever-growing picture archives and other needful things easily get out of control, especially if you use your Mac for editing movies, making music or simply download lots of data from torrents the web.

Let’s see what you can do about this…

Huge apps and fat binaries

Look at the /Applications folder and you’ll see that many Mac apps are sized 100-500 MB. And these are just daily use apps like iTunes (150 MB) or iPhoto (330 MB). Loving Steam games? Then add about 9 GB for Team Fortress 2, 8 GB for Left4Dead and 2 GB for Killing Floor or Portal and so on and so forth.

There is a way to nearly half the space occupied by the apps (not games, unfortunately :D). As you may know Apple has switched from PowerPC processors to Intel a few years ago, but there’re still lots of old Macs with PowerPC processors. In order to support both architectures many developers distribute their applications as universal binaries, also known as fat binaries. These applications contain two versions of the same app and you’ll likely never ever need one of them.

In addition to that, most Mac applications are localized, so a single application can be used by, say, both English and German users. That also has a cost of extra space being taken by data you don’t really need.

Why not just remove redundant localizations or support for processors you don’t even have? That shouldn’t be too hard, right?

Not really. In the real world we happen to live in a typical picture looks like this: you run a binary stripper, it reports saving you lots of disk space, but in a day or two you find out that some of the apps simply no longer work! That sucks. No, that REALLY SUCKS. It happens because some developers (Adobe, for instance) add integrity checks into their apps as an anti-piracy measure. If such an app finds itself modified, it thinks it has been cracked and quits immediately. To work around this, advanced binary strippers maintain a regularly updated don’t-touch-me list of apps, but it’s still a Russian roulette — odds are that some apps may stop working after such an optimization. Also note that if you update an app, it becomes unoptimized again, and you have to repeat the procedure over again.

As by the Murphy’s law, the apps that cannot be stripped are often the biggest space wasters (take a look at Adobe CS). At the bottom line, stripping binaries does not turn out to be a really big space saver, the typically reported figure being somewhere around a few GBs. It may still be worth the trouble for MacBook Air owners, where disk space constraints are especially tight.

Good riddance of unneeded apps

It’s so great that on Mac most applications can be installed with a simple drag-and-drop. However, there is a serious drawback of this approach when it comes to uninstalling the no longer needed apps. If you just drag-and-drop an app to the Trash, it will not remove any related data, such as configuration files and databases. While in most cases it’s not a big deal (maybe a few megabytes or less), some applications, like web browsers, may forget a gigabyte or two. You can see it yourself, just open the ~/Library/Application Support folder.

For example, on my Mac I have 1Password and Google Chrome that store over 1 gigabyte of their data, and Fontcase and LittleSnapper databases are also close to 1 GB. If I decide to trash these apps, all their data files will still remain on my disk, unless I remove them manually. Alternatively, I can use a special uninstaller app, like AppZapper, to have the cleanup job done for me.

The uninstallers also have their downsides. They may skip certain unneeded files or delete something useful. The good thing is that in most cases you can preview the files they are about to remove, and thus feel a bit more confident. At least, they don’t automagically damage random applications :)

Compress and archive

In Mac OS X 10.6 Apple has finally introduced the on-the-fly compression into the file system. Of course, in no way it’s a magic bullet for saving disk space, but it works pretty well on large portions of read-only data. It makes no sense to compress movies or music, but it can save you some space on applications or text documents. To enable the compression, you can exercise with the command line or just use an app like Clusters.

Mess my Mac

There is an undying myth, particularly wide spread among people who recently switched to Mac from Windows, that their Mac needs regular cleaning in order to keep it healthy, that is to run smoothly and fast. The truth is that unlike early versions of Windows, Mac OS X doesn’t really need much maintenance, and if you don’t do it, in most cases you will not notice any difference. Besides, Mac OS X does some regular self-maintenance automatically, at times when you are away.

While automatic maintenance and cleanup applications may be helpful, be cautious when using them, and backup your system (Time Machine is your best friend). Always double-check the cleanup options, because it’s better to leave an extra megabyte or two than to find out that a chat history is missing or the cleaner wiped out something needful just because it can.

If you really (really?) think you need a maintenance tool for your Mac, use the tried and true and free Onyx application, and be careful with newborn optimizers from unknown developers.

Computers cannot outsmart humans

There is also a totally different approach to recovering your disk space, implemented in some other apps.

Instead of being too smart, they display a visual map of how your drive is used. Such a representation allows you to spot large folders and files in a blink of an eye.

Unlike the slimmer apps, the visualizing apps don’t rigidly delete some pre-defined set of files, no matter how large or negligibly small those files may be, but help the human make the decision and delete the biggest space wasters in the first turn.

I personally like this approach best (hell, otherwise we wouldn’t create DaisyDisk!), because it’s the most efficient one. Indeed, in many cases a lot of disk space is wasted by a small number of large files like archives, movies or cached data that somehow gets out of control. Automatic trimmers would not find those space hogs and could not understand they were lumber, while disk visualization tools give you a valuable insight about what’s really filling up your disks.

There’s no magic bullet

Once you’re really low on disk space, I’d recommend to scan your drive with a visualization tool like DaisyDisk. This will reveal the real space wasters, but it has its limitations. In order to get a few more gigabytes, consider removing a few apps or slimming them down with, say, Xslimmer or archiving your Applications or Documents folder with Clusters  (it sometimes even makes sense to compress some rarely used documents to ZIP/7ZIP formats). Whatever you choose to do, do not forget to make regular backups — your data is way more important than disk space.