{"id":"mac-storage-basics.what-is-the-3-2-1-backup-rule","url":"/faq/mac-storage-basics/what-is-the-3-2-1-backup-rule","category":{"id":"mac-storage-basics","title":"Mac storage basics"},"subcategory":{"id":"time-machine","title":"Time Machine basics"},"question":"What is the 3-2-1 backup rule?","alt_questions":["how many backups should i have","best backup strategy mac","offsite backup rule","backup rule of thumb","three copies two media one offsite"],"short_answer":"Keep 3 copies of important files, on 2 different kinds of storage, with 1 copy kept off-site — for example the Mac, a Time Machine drive and a cloud or off-site copy.","answer_markdown":"It's a simple rule of thumb for not losing files: keep **3** copies of anything important, on **2** different kinds of storage, with **1** copy somewhere else (another building, or a cloud service).\n\nFor a Mac that might be: your files on the Mac, a Time Machine backup on an external drive, and a third copy in a cloud backup or on a drive you keep elsewhere. Moving files to an external drive to free space is not a backup on its own — the drive then holds the only copy, so back it up too.","answer_html":"

It's a simple rule of thumb for not losing files: keep 3 copies of anything important, on 2 different kinds of storage, with 1 copy somewhere else (another building, or a cloud service).

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For a Mac that might be: your files on the Mac, a Time Machine backup on an external drive, and a third copy in a cloud backup or on a drive you keep elsewhere. Moving files to an external drive to free space is not a backup on its own — the drive then holds the only copy, so back it up too.

","answer_text":"It's a simple rule of thumb for not losing files: keep 3 copies of anything important, on 2 different kinds of storage, with 1 copy somewhere else (another building, or a cloud service).\n\nFor a Mac that might be: your files on the Mac, a Time Machine backup on an external drive, and a third copy in a cloud backup or on a drive you keep elsewhere. Moving files to an external drive to free space is not a backup on its own — the drive then holds the only copy, so back it up too.","tags":["backup","strategy","time machine"],"related":[{"id":"mac-storage-basics.is-time-machine-enough-as-a-backup","question":"Is Time Machine on its own enough of a backup?","url":"/faq/mac-storage-basics/is-time-machine-enough-as-a-backup"},{"id":"mac-storage-basics.can-time-machine-back-up-to-icloud","question":"Can Time Machine back up my Mac to iCloud?","url":"/faq/mac-storage-basics/can-time-machine-back-up-to-icloud"}],"applies_to":"all","last_reviewed":"2026-10-01","title":"What is the 3-2-1 backup rule? — Storage Studio FAQ","description":"Keep 3 copies of important files, on 2 different kinds of storage, with 1 copy kept off-site — for example the Mac, a Time Machine drive and a cloud or off-site copy.","crumbs":[{"name":"Home","path":"/"},{"name":"FAQ","path":"/faq/"},{"name":"Mac storage basics","path":"/faq/mac-storage-basics/"},{"name":"What is the 3-2-1 backup rule?","path":"/faq/mac-storage-basics/what-is-the-3-2-1-backup-rule"}],"jsonld":{"@context":"https://schema.org","@type":"FAQPage","url":"https://storagestudio.us/faq/mac-storage-basics/what-is-the-3-2-1-backup-rule","inLanguage":"en","dateModified":"2026-10-01","mainEntity":[{"@type":"Question","name":"What is the 3-2-1 backup rule?","alternateName":["how many backups should i have","best backup strategy mac","offsite backup rule","backup rule of thumb","three copies two media one offsite"],"acceptedAnswer":{"@type":"Answer","text":"It's a simple rule of thumb for not losing files: keep 3 copies of anything important, on 2 different kinds of storage, with 1 copy somewhere else (another building, or a cloud service).\n\nFor a Mac that might be: your files on the Mac, a Time Machine backup on an external drive, and a third copy in a cloud backup or on a drive you keep elsewhere. Moving files to an external drive to free space is not a backup on its own — the drive then holds the only copy, so back it up too.","url":"https://storagestudio.us/faq/mac-storage-basics/what-is-the-3-2-1-backup-rule"}}]},"fragment":"
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Mac storage basics · Time Machine basics

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What is the 3-2-1 backup rule?

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Short answer: Keep 3 copies of important files, on 2 different kinds of storage, with 1 copy kept off-site — for example the Mac, a Time Machine drive and a cloud or off-site copy.

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It's a simple rule of thumb for not losing files: keep 3 copies of anything important, on 2 different kinds of storage, with 1 copy somewhere else (another building, or a cloud service).

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For a Mac that might be: your files on the Mac, a Time Machine backup on an external drive, and a third copy in a cloud backup or on a drive you keep elsewhere. Moving files to an external drive to free space is not a backup on its own — the drive then holds the only copy, so back it up too.

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