{"id":"external-drives.what-checks-run-before-transfer-drive-starts","url":"/faq/external-drives/what-checks-run-before-transfer-drive-starts","category":{"id":"external-drives","title":"External drives"},"subcategory":{"id":"upgrading-and-copying","title":"Upgrading, transferring and backing up the drive"},"question":"Why won't Transfer Drive or Backup Drive let me pick a drive?","alt_questions":["No Drive Available in Transfer Drive","New drive not allowed for transfer","Transfer Drive says drive too small","Why is my destination drive greyed out?","transfer drive requirements","Which drives can be a Transfer Drive destination?"],"short_answer":"The destination must be an external APFS or Mac OS Extended drive with room for everything on your current drive, and not already a Storage Studio drive for this Mac. Slow drives need confirming; unsuitable ones can't start.","answer_markdown":"Before anything copies, the destination is checked. It must be:\n\n- an **external** drive — your internal disk and network shares are never offered;\n- formatted **APFS** or **Mac OS Extended**;\n- big enough for **everything on your current drive**;\n- **not already** a Storage Studio drive for this Mac.\n\nA quick speed test runs too. A slow drive or one with cautions asks you to confirm; an internal, network or too-small drive can't be started at all. If nothing suitable is connected you'll see **No Drive Available** — plug one in and press **Refresh**.","answer_html":"

Before anything copies, the destination is checked. It must be:

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A quick speed test runs too. A slow drive or one with cautions asks you to confirm; an internal, network or too-small drive can't be started at all. If nothing suitable is connected you'll see No Drive Available — plug one in and press Refresh.

","answer_text":"Before anything copies, the destination is checked. It must be:\n\n- an external drive — your internal disk and network shares are never offered;\n- formatted APFS or Mac OS Extended;\n- big enough for everything on your current drive;\n- not already a Storage Studio drive for this Mac.\n\nA quick speed test runs too. A slow drive or one with cautions asks you to confirm; an internal, network or too-small drive can't be started at all. If nothing suitable is connected you'll see No Drive Available — plug one in and press Refresh.","tags":["transfer drive","requirements","troubleshooting"],"related":[{"id":"external-drives.transfer-drive-says-already-a-storage-studio-drive","question":"Why won't Transfer Drive use a drive that is already a Storage Studio drive?","url":"/faq/external-drives/transfer-drive-says-already-a-storage-studio-drive"},{"id":"external-drives.how-do-i-move-everything-to-a-new-external-drive","question":"How do I move everything to a new, bigger external drive?","url":"/faq/external-drives/how-do-i-move-everything-to-a-new-external-drive"},{"id":"external-drives.transfer-drive-vs-backup-drive","question":"What's the difference between Transfer Drive and Backup Drive?","url":"/faq/external-drives/transfer-drive-vs-backup-drive"}],"applies_to":"all","last_reviewed":"2026-10-01","title":"Why won't Transfer Drive or Backup Drive let me pick a drive? — Storage Studio FAQ","description":"The destination must be an external APFS or Mac OS Extended drive with room for everything on your current drive, and not already a Storage Studio drive for this Mac. Slow drives need confirming; unsuitable ones can't start.","crumbs":[{"name":"Home","path":"/"},{"name":"FAQ","path":"/faq/"},{"name":"External drives","path":"/faq/external-drives/"},{"name":"Why won't Transfer Drive or Backup Drive let me pick a drive?","path":"/faq/external-drives/what-checks-run-before-transfer-drive-starts"}],"jsonld":{"@context":"https://schema.org","@type":"FAQPage","url":"https://storagestudio.us/faq/external-drives/what-checks-run-before-transfer-drive-starts","inLanguage":"en","dateModified":"2026-10-01","mainEntity":[{"@type":"Question","name":"Why won't Transfer Drive or Backup Drive let me pick a drive?","alternateName":["No Drive Available in Transfer Drive","New drive not allowed for transfer","Transfer Drive says drive too small","Why is my destination drive greyed out?","transfer drive requirements","Which drives can be a Transfer Drive destination?"],"acceptedAnswer":{"@type":"Answer","text":"Before anything copies, the destination is checked. It must be:\n\n- an external drive — your internal disk and network shares are never offered;\n- formatted APFS or Mac OS Extended;\n- big enough for everything on your current drive;\n- not already a Storage Studio drive for this Mac.\n\nA quick speed test runs too. A slow drive or one with cautions asks you to confirm; an internal, network or too-small drive can't be started at all. If nothing suitable is connected you'll see No Drive Available — plug one in and press Refresh.","url":"https://storagestudio.us/faq/external-drives/what-checks-run-before-transfer-drive-starts"}}]},"fragment":"
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External drives · Upgrading, transferring and backing up the drive

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Why won't Transfer Drive or Backup Drive let me pick a drive?

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Short answer: The destination must be an external APFS or Mac OS Extended drive with room for everything on your current drive, and not already a Storage Studio drive for this Mac. Slow drives need confirming; unsuitable ones can't start.

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Before anything copies, the destination is checked. It must be:

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  • an external drive — your internal disk and network shares are never offered;
  • formatted APFS or Mac OS Extended;
  • big enough for everything on your current drive;
  • not already a Storage Studio drive for this Mac.
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A quick speed test runs too. A slow drive or one with cautions asks you to confirm; an internal, network or too-small drive can't be started at all. If nothing suitable is connected you'll see No Drive Available — plug one in and press Refresh.

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Last reviewed

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