External HD - Mac Partition + Windows Partition

in Genius Bar edited January 2014
I have an external 500GB Lacie d2 Quadra hard drive which I've been using exclusively with Windows for a while now, with no problems. It has two NTFS partitions - primary partition 320GB and extended partition 180GB.

I recently got a new iMac, and want to use the HD with it as well. My plan was to simply convert the first partition to a HFS+ disk, so that i have one HFS+ partition and one NTFS partition.

So I moved all the windows content onto the 180GB partition, and plugged it in to my iMac. Both partitions mounted successfully on the Mac as NTFS disks. I opened up Disk Utitlity on the mac, selected the first partition (320GB), and chose Erase (Mac OS Extended). It started, but then stopped a few seconds later and unmounted. I tried to manually mount it again, but it said it couldn't and, and suggested I try First Aid. I went to First Aid for that partition, but all options were greyed out. So i tried to erase it again - same problem. Can't seem to do anything to make it work - it just gives up with no error message. The 180GB partition was unaffected - it's still fine.

When i plugged the hard drive back into windows, it recognised the first partition as not being formatted after the mac fiasco, and it let me format it using NTFS and worked no problem.

Put it back in my Mac and tried to erase first partition as HFS+ again - no luck. Same problem exactly.

Can anybody help? Is a HFS+/NTFS disk possible? Should the NTFS partition be the primary one and the HFS be the extended one (i haven't tried that)? Any other insight?




  • Reply 1 of 1
    Mac OS X has a really hard time manipulating any kind of NTFS partitions. Every time I've tried, it seems to do it, but try formatting the desired NTFS as FAT first, then go from FAT to HFS if you feel the need.

    Note: You'll need to do this on the Mac, of course. Windows XP and Vista have an absolutely ridiculous restriction that prevents it from creating FAT volumes bigger than 32 GB. Mac OS X, thankfully, is unaffected by this restriction. If you can get ahold of a Windows 2000 machine, however, it can create a FAT volume as large as you want.
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