Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have an external hard drive that was connected to a Mac and formated and written to by Time Machine.

Is it usable on a Windows System? Could I reformat it as NTFS and leave it connected to a Windows 7 machine and use Time Machine on the Mac to back up over the network?

If I do that, can Time Machine restore a Mac system over the network like that?

share|improve this question
up vote 1 down vote accepted

If you have the original Snow Leopard installation CD, you can use that CD install the HFS+ driver in Windows. It only allows Windows to read the HFS+ partition, no writing.

I actually have a 1TB hard disk, and partitioned into one NTFS and one HFS+. The NTFS partition is used for Windows, and the HFS+ used for the Time Machine backup.

share|improve this answer
What tool and on what OS did you create the partitions? – BrianK Dec 27 '11 at 0:56
I used the Windows to create the partitions, one in NTFS, one in FAT. And then used the OS X to remove the FAT partition and recreated the HFS+ partition. – kukoo Jan 7 '12 at 15:26

No, time machine cannot back up to an NTFS formatted drive. Reformatting the drive will make the time machine backup unusable without attempting a recovery which may or may not be successful.

share|improve this answer

MacOS uses HFS+ as its default file system. Since Time Machine, as Mac OS's backup tool, needs to be able to represent every structure that may occur on the Mac's hard drive in the backup, the backup volume must be formatted as HFS+, too.

Since Windows does not have drivers for HFS+, you won't be able to use the drive on a Windows machine. Conversely, if you formatted it with NTFS, Time Machine would no longer be able to represent everything on the Mac's HFS+ partition in the backup.

share|improve this answer

There are drivers from Mediafour and Paragon that will allow you to get R/W access to HFS(+) partitions under Windows.

Time Machine uses sparse bundles to store backup files if used over a network, so theoretically you can store it on any partition type with any OS. However, Apple only allow you to use it over AFP and there are checks to prevent non-Time Capsule devices being used.

You can hacks around this, but that also means if your system crashes, you'll have to reinstall first before you can restore anything. (Also note TM backup to an external hard disk may be in a different format, so if you will not be able to access your old backups over the network.)

In the end most of such questions ends with an answer like use rsync instead (and it really is a more flexible and though more involving solution).

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .