Leopard Disk Utility Format Issue Screws With Time Machine (But There’s An Easy Fix)

The bad news is, we have discovered a Leopard-related issue that may very well throw a monkey wrench into your Time Machine. Anyone trying to use Time Machine with a previously PC-formatted drive could be at risk. The good news is, there is an easy—albeit none-too-obvious—fix. Here’s the dilly-o:

After I upgraded my MacBook Pro to OS X Leopard, the first thing I did was grab a brand-new Maxtor USB drive and format it to Mac OS Extended (Journaled) using Disk Utility, just like I had countless times before. As soon as I erased the disk, Time Machine popped up as promised, and asked if it could use the disk for backup. I said yes, and was on my merry way. Only I wasn’t.

Time Machine ran for a bit, and then crapped out after about 10GB. I went into Disk Utility and saw that although the partition was formatted Mac OS Extended (Journaled), the volume itself still said FAT32. I clicked Erase to reformat the drive, and got the format failure error you see above.

I tried this with FAT-formatted drives from Seagate, Iomega and HP as well. Each time I saw the same thing. I could reformat the partition to Mac OS Extended (Journaled), and Time Machine would recognize it. Get Info would say that it was formatted correctly. But Disk Utility showed that the volume was formatted for PC. Inevitably, if the Time Machine backup was greater than 10GB, there were problems. Worst of all, if I dared try to format the volume for Mac, I would get the dreaded error, and the disk would be temporarily unmountable.