Q The 1 terabyte hard disk that I use for Time Machine backups is now reported as being full. As I can open the Backups.backupdb folder on it to view all the backed up folders and files, can I now remove all those older than six months, for example, to free up space for future backups?

A You really do not want to do that, but leave Time Machine to handle its own backups. What appear to be real files and folders on the backup volume are mostly links to the original files; trash an earlier backup containing the original to which those links point and you could render more recent backups useless.

If your backup drive is an internal disk, now would be a good time to replace it with a fresh disk, so you can keep your full backup disk as an archive copy.

If you do not want to pay for a new hard disk, then you can thin files from an existing backup safely. Open the Time Machine restore application, locate some old files that you want to remove (and know that you do so safely), then click on the gear icon in Time Machine’s special Finder window to reveal its popup menu. In that, you can choose between deleting that backup, or all backups of the selected items, to weed out older material and free up space.

Updated from the original, which was first published in MacUser volume 26 issue 20, 2010.