Data Backup Digest

Time Machine is a built-in automated backup application that comes on all new Mac computers. It is meant to work with external hard drives and Apple’s Time Capsule, which is its product line of wireless Network Attached Storage (NAS) devices. Time Machine was first released in 2007 for Mac OS 10.5 Leopard and has been included in every version of the Mac operating system since. Time Machine is popular because it is free to use on every Mac, automates backing up, keeps many versions of files, and has a simple interface.

Like any other backup program, Time Machine automatically makes copies of all the files on your hard drive. Time Machine essentially takes a picture or snap shot of your computer and copies that to the external hard drive. What makes Time Machine special when compared to other backup programs is that it keeps versions of files. Time Machine stores a one snap shot of your hard drive that is taken every hour for the past day. It also keeps a snap shot of every day for the past month and weekly snap shots. Time Machine will keep weekly backups until that hard drive is full and then it starts to overwrite previously saved data. Since Time Machine keeps so many versions of files, it easy to find the version of a file you want even if it’s not the most recent version.

Since Time Machine keeps so many different versions of all files, it’s important to have an external hard drive that is many times bigger than the internal hard drive that is being backed up. Time Machine will keep weekly backups indefinitely until the hard drive is full.

Time Machine is purely for making local backups. The data isn’t stored in the cloud so it could fall prey to house fires, flood, theft, or just drive failure. People that want online and offsite backups should consider also paying for a service like CrashPlan, Mozy, or Carbonate. Most online backup service have some free version and paid plans that include more storage.

A downside to Time Machine is that is does not create a bootable disk. This means if you swapped the external backup hard drive for the internal hard drive, the Mac wouldn’t work. Creating a bit per bit duplicate copy of a drive is called cloning and a cloned hard drive can be swapped in for the original with no problem. Time Machine is great for keeping backups and versions, but someone who wants to have no down time after an internal hard drive fails and just wants to swap in another hard drive should consider using a cloner. Popular hard drives cloners include Carbon Copy and SuperDuper.

Time Machine is a great tool for people who want a local backup of all their files and multiple versions of files all on the same external hard drive. It won’t make a bootable backup or backup the data online, but it makes local backing up easy. Combining Time Machine with an online backup service would make for an almost perfect backup system.