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As Apple(s AAPL) starts to make more and more Macs with solid state drives by default, like the new MacBook Airs, and not yet available Mac Pro, storage space on your Mac is becoming a premium once again. This is especially true when you only have 128 GB of storage on your new 11-inch Air, which is the only size option you have at the $999 price point.

While the performance gains of having an SSD inside your Mac instead of a SATA drive are worth it, managing your free space will still be a task that you need to keep on top of. And while you may think that the cloud will come to your rescue and free up some of that space, you will find that behind the scenes many of the cloud-based services are just managing a local synced copy of the files you thought were being stored in the cloud.

Here’s how you can identify where all of your hard drive space is going, and a few techniques for managing your free space more effectively.

Locating Large Files. Finding out which files and folders on your Mac are taking up all of your hard drive’s space is half the battle. A good drive space utility that is among the first apps I install on every Mac I own is DaisyDisk ($9.99, Mac). It’ll let you quickly scan your Mac’s hard drives, including attached external drives, and see which files and folders are taking up the most space. The user interface starts out at the top-most folders, and allows you drill down and see exactly where the largest amount of storage is being used.

Sleep Memory Cache. One of the larger files you will find when using DaisyDisk is what is known as the Sleep Memory Cache file located in the /var/vm folder. Whenever your Mac goes to sleep, it saves the state of the system’s memory into a file on the hard drive. This file will be approximately the same size as the amount of memory you have installed on your Mac. So if you have a MacBook Air with 8GB of memory and a 128GB SSD, that 8GB Sleep Memory Cache file will take up a little over 6 percent of your available hard drive space. There is not much to do about this. There are techniques for preventing your Mac from ever going to sleep, but that is not recommended and will challenge any battery life optimizations you may have made. Not to mention it could also result in lost data if you happen to run out of power when your files are still open.

Clearing Other Caches. There are, however, caches that you can clear out on a routine basis without much to worry about. A great utility that can help expedite this process is MacCleanse ($19.99, Mac). This will help you locate and remove temporary files like browser caches, emptying the trash, history, log files, recently accessed files lists, user logs, the list is quite extensive. MacCleanse has a series of profiles that you can use that will first scan your hard drive looking for known caches to delete. You can then select which caches you want to delete. It even has the ability to create your own profile of files and caches to keep clean. There is a convenient status page that will display upon startup of the app that will tell you how much space you can save before running the delete.

Local iCloud Files. Like the Sleep Memory cache there are other files that you will find that take up space that you best leave alone. One thing you need to know about iCloud data for your Mac apps is that the data is not all located in the cloud. In fact, many of the data files are replicated on your Mac. Each user account on your Mac will have these files stored locally in their ~/Library/Mobile Documents/ folder. Do not remove these files from your Mac, if you do, they will also be removed from iCloud.

Photo Stream. Like your iCloud data files, your Photo Stream is stored locally on your Mac. And if you happen to have several shared photo streams, with up to 1,000 photos each, this can quickly start to consume your entire drive. These images will be stored inside of your iPhoto or Aperture library. When you option-click on your library bundle and select show package contents, you will find where these files are located. Turning off Photo Stream in your iCloud System Preferences on your Mac is about the only way you can clear up this space. Otherwise, your Mac will just keep trying to update your Photo Stream files. But be aware: turning this feature off will mean that your Photo Streams will not show up on your Mac.

iOS Device Backups. If you are still managing backups of your iOS devices on your Mac, you may find that the backup files are taking up an increasing amount of space, especially if you have been keeping up with your device upgrades over the years. You may now have several backup files for older iOS devices that you no longer care about. These device backup files are located in each user’s “~/Library/Application Support/MobileSync/Backup” folder. You can select which ones to delete from within iTunes. Open the iTunes Preferences and click on the Devices tab. Here you will see a list of all of the iOS device backups you have stored on your hard drive. Just be sure not to delete your most recent device backup. If you do, just be sure to make another one right away.

iOS Device Updates. Now that you can update your iOS device over the air, you no longer need to download and tether your device to iTunes to get the latest iOS updates on your devices. If you still do update your iOS devices from iTunes on your Mac, or you used to, you may find that several versions of the update files are still on your hard drive. These files would be located in each user’s “~/Library/iTunes/iPhone Software Updates” folder. Unless you are in the middle of performing an update, you can remove these files from your Mac. If they are ever needed again, iTunes will re-download them as needed.

iTunes Downloads. The media stored inside of your iTunes Library is another location where you may find a lot of space being used up. Depending on the size of your library, keeping it located on your Mac may no longer be an option. You can opt to subscribe to iTunes Match, and keep your music in iCloud. That way you only download the songs you want to listen to, when you want to listen to them.

iOS App Downloads. It’s not just media files that are located in your iTunes Library. Your iOS apps may also be located there as well. This is especially likely if you have requested your local iTunes Library to download all app purchases automatically. This is not as necessary as it once was, as you can now access all of your purchased apps on iTunes in the Cloud directly from your iOS devices.

Podcast and iTunesU Subscriptions. If you subscribe to several different podcasts, there are options available to you to help keep the space allocated to your podcasts at a minimum. If you do actually listen to or watch all of the podcasts you subscribe to on your Mac, at least consider configuring iTunes to keep only the most recent unread episode of your favorites. That way you are not wasting space with episodes that you have already reviewed.

Archive Your Downloads. Like emptying your trash folder, archiving your downloads folder to an external drive should become a routine practice. Unfortunately, this is a manual process. Your best bet is to use a folder sync utility like the one that comes with LaCie drives and is also available in the Mac App Store called Intego Backup Express ($7.99, Mac). This utility will allow you to quickly move your downloads folder to an external drive.