after i back up my computer using an external hd and time machine can i erase data from my computer?

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Western Digital My Book for Mac

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2 Answers from the Community

  • Best Answer:

    No. The whole point of a backup is to have your data in two (or more) locations, so a failure in any one place does not mean total loss of your data. Furthermore, Time Machine backups will prune the oldest data as the backup drive gets full (always preserving what is needs to reconstitute your internal drive in its current state). So if you back up a folder of music, say, then delete it from your internal drive, that backed-up folder could eventually be pruned.

    To move data off your internal drive that you want to keep, you will need a second external drive. Move the data to that, then make sure Time Machine is backing up both the internal and the new external drive to the Time Machine drive.

    All hard drives fail--think of them like light bulbs in that respect. And arrange your data management accordingly.

    I speak as an independent Mac consultant.

  • Yes. That is the one of the purposes of an external hard drive, to free up storage on your computer. The other purpose of course, is protection against losing files. Once you backup files to an external device, it would be prudent to also backup all or some of your files to either iCloud (some space free with option to buy more storage space) or an off-site service such as Mozy or Carbonite. Their plans are reasonable. Imagine your external HD becoming stolen, lost in a fire, or somehow damaged. In short, backup files to an external HD AND off-site. This is standard operating procedure for most corporate contingency plans.