One Backup Disk for Windows and OS X

Unfortunately the preferred file systems for Windows XP and Mac OS X do not permit users to read and write data between each other. NTFS is the recommend file system on Windows XP and HFS+ is the preferred file system on OS X. Recent versions of OS X will read NTFS partitioned disks, but will not write to the partition. I have a PC and Mac, but my PC is my primary machine. I want one disk drive that I can swap between my Windows and OS X computers, so I found the overall easiest solution to be a Mac-formatted FAT32 single-partition external disk drive.

Formatting the disk

I formatted a disk in OS with the Disk Utility application. The key was to format the disk with the Mac and not with the PC. This Microsoft Knowledge Base article explains that FAT32 supports disk sizes up to 2TB, but due to limitations on your BIOS you may only be able to create a bootable partition of 7.8GB, which would not suit my purposes.

The overall most simple approach is to format the drive in OS X as a FAT32 disk so that it is readable and writeable by OS X and Windows.

1. Connect your external hard drive via Firewire or USB
2. open “Disk Utility” and select your disk
3. Choose the “Erase” tab
4. From the “Volume Format” pulldown menu choose “MS-DOS File System”
5. Give your drive a name (I called mine “Backup”) and hit Erase.

I successfully created an 80GB FAT32 partitioned drive in this way that I can now use to move pictures, music, and documents between my Mac and PC.

Use OS X to create MS-DOS file system partition

There are certainly more advanced backup options, involving networks, SAMBA and CIFS protocols, rsync, and other tools. Please share any useful links. In the future I plan to explore automated backups, and version controlled backups. In the meantime, this backup method will suffice.

More resources

• General tips and tutorials: Mac OS X Hints
• Backing up a mixed OS X and Windows 2000 Home Network
• Sharing Files Between Windows XP and Mac OS X
• X vs. XP: Backing Up and Restoring Files