can u delete data from your hard disk once you have backed up time machine? time machine?

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You can but you shouldn't do it. That's because when the external disk where you store the Time Machine backups gets full, Time Machine will start deleting older backups. If you have deleted the original files from your hard disk and Time Machine deletes the backups that contains them, you will lose these files and you won't be able to recover them.

Instead, what you can do is to move them to another external disk after being backed up in Time Machine. Doing this, you won't lose your files unless this external disk gets damaged

Hi a,

Data should always be saved in at least two different places (your MBP and an external HD for TM). Given that, you could use two different external HDs to save your data to, then it would be ok to delete it from your MBP.