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I have a Buffalo HD-CEU2 1TB external hard drive. I want to use it to back up my Mac and a Windows machine. If possible I would like to use the Time Machine software on my Mac to do this and just use the external hard drive as I don't actually want to go out an buy a Time Machine device.

At the moment my Time Machine software gives me error code -36, when it tries to backup.

Sorry, I don't actually have the exact error message details to hand, I'll update the post when I get home.

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Afaik, error -36 is a basic IO error. What is your Buffalo drive partitioned like currently? Have you already been able to make backups with it? – slhck Jan 31 '12 at 12:25
Thanks Afaik, I'm in work at the moment, so I'll check when I get home this evening, but I think its SMB. I can access the files on it with no issues, its just the Time Machine software that's not working. – Stephen Jan 31 '12 at 12:50
Time Machine requires HFS+ partitions. – Daniel Beck Jan 31 '12 at 13:01
It's probably not SMB, that is a protocol used to access networked file shares. It's probably either FAT32, NTFS, or HFS+. As Daniel said, Time Machine only works with HFS+ partitions. You can quickly check what you currently use by entering diskutil list in the terminal. It would show Apple_HFS next to the name of the drive when it's an HFS+ partition. – slhck Jan 31 '12 at 14:28
up vote 2 down vote accepted

No, but it's probably easiest.

As has been pointed out in the comments, Time Machine requires a drive formatted as Mac OS Extended (HFS+). I believe this requirement can be waived if you're Time Machining to a network drive (Time Machine creates its own HFS+ disk image), but you don't want to buy extra hardware.

You can get read/write Windows drivers for HFS+ (e.g.), but as far as I know they all cost. I also don't know how well your favourite Windows backup utility would cope with an HFS+ drive - if you do go down this route, check that recovery works before you need it.

If you're willing to accept an alternative Mac backup program to Time Machine, you could format the drive as FAT32, but that's an old file system, and has various limits - most prominently, a maximum file size of just 4GB. You could also install NTFS drivers on your Mac (e.g.) and there are free options this time. That said, with both NTFS and FAT32, there is the risk that some Mac files (mainly older ones, admittedly) will have problems because their resource fork gets mislaid in either the backup or recovery.

So, in short, you're probably best using Disk Utility in /Applications/Utilities to partition your drive into an HFS+ partition for your Mac backups and an NTFS partition for your Windows backups. That way, each operating system can deal with its normal file system, and files in the backup will be on the same type of file system as they are in the original, which means one less possible problem if the worst happens and you need to restore.

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Unfortunately Time Machine requires an HFS+ filesystem which Windows cannot read or write to by default. Apple recently released HFS+ read only drivers for Windows as part of the Boot Camp driver pack with OS X 10.6, but if you want to write to it you're out of luck.

An alternative would be to format the drive as FAT32, but there's a file size limit of 4GB. This will let you read and write on both Windows and OS X, but you won't be able to use it for Time Machine.

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