free up storage
if i permanently erase device backups to free storage space, will these backups be on my external hard drive if i backed up with time machine?
MacBook Pro
Question marked as
Top-ranking reply
Whatever is on your computer will be on your Time Machine backup drive assuming Time Machine is backing up automatically and no files are in the Exclude list.
If you delete files on your computer, then they will be deleted from the backup based on the following:
Time Machine deletes older files if they have been deleted from the source when it needs space on the backup drive for a new incremental backup. Time Machine "thins" it's backups; hourly backups over 24 hours old, except the first of the day; those "daily" backups over 30 days old, except the first of the week. The weeklies are kept as long as there's room.
How long a backup file remains depends on how long it was on your Mac before you deleted it, assuming you do at least one backup per day. If it was there for at least 24 hours, it will be kept for at least a month. If it was there for at least a week, it will be kept as long as there's room. By default, Time Machine backs up hourly.