Macworld reader David wonders whether a drive used for Time Machine backups can also store other files, or whether that could cause problems. The good news is that you don't have to devote an entire drive to Time Machine backups, although you may certainly choose to do so.
macOS writes all the archived files related to Time Machine to locations within a folder called Backups.backupdb. Everything else on the drive gets ignored. However, as a drive fills up, Time Machine starts deleting the oldest snapshots, which are retained starting seven days after an initial hourly backup as weekly snapshots.
Depending on how large your archives are and how much capacity the drive has, you may want to leave as much space free for Time Machine backups as possible.
Ask Mac 911
We’ve compiled a list of the questions we get asked most frequently along with answers and links to columns: read our super FAQ to see if your question is covered. If not, we're always looking for new problems to solve! Email yours to firstname.lastname@example.org including screen captures as appropriate, and whether you want your full name used. Every question won’t be answered, we don’t reply to email, and we cannot provide direct troubleshooting advice.