New Iomega drives ship with NTFS filesystems, formatted for MSDOS. They must be reformatted to work with Mac OS X.

However when attempting to format these drives you may get this error:

"Partition size not a multiple of 4k"

Here's how to fix it.

1. Open Disk Utility and select the drive. Click Partition tab : Options : GUID Partition Table (assuming you have an Intel-based Mac). Click OK.

   




2. Select "2 Partitions" (or higher) from the Volume Scheme dropdown menu. Create two or more partitions of any size. They can be equal or not - according to your preference. Select Mac OS Extended (Journaled) from the Format Menu. Enter names for each partition, then click Apply. You may be able to succeed with 1 partition, but I was not able to, so created one small partition and one large one.

   

3. You should see the "Formatting..." progress bar appear down in the footer area of the window. It does not take very long to complete the process, then the drives will mount.

   

Thanks to holmahenkel and
chjr7777 from the Apple discussion forums.