Sign up ×
Ask Different is a question and answer site for power users of Apple hardware and software. It's 100% free, no registration required.

My 1 TB Time Capsule drive is full with Time Machine backups. I'd rather spend $130 on a 3 TB drive than $500 on a new 3 TB Time Capsule.

Is an external drive attached to a Time Capsule supported for Time Machine backups? I have read that trying to use Time Machine with an Airport Extreme and an attached external drive is not supported and is in fact unreliable. Does that extend to Time Capsules with an external drive?

I realize that a Time Machine backup cannot be split across drives -- I would move entire backups to the 3 TB drive.

I bought my 1st generation Time Capsule (MB277LL/A) in 2008. I am running Mountain Lion.

share|improve this question

1 Answer 1

up vote 3 down vote accepted

It is not officially supported. "Time Machine can’t backup to an external drive that's connected to an AirPort Extreme, Time Capsule, or a drive formatted for Microsoft Windows (NTFS or FAT format)." This is usually because of issues with the network file system not guaranteeing that writes have completed on disk before giving a "success" status.

share|improve this answer
Thanks. Dangnabit. I can see how they would not be motivated to solve that problem ... – Mark Adler May 27 '13 at 15:20
I don't understand the “network file system” explanation. – Nicolas Barbulesco Oct 12 '13 at 16:59

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.