Creating HFS Disks and Images Under OS X 10.6 Leopard

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Creating HFS Disks and Images Under OS X 10.6 Leopard

In case you haven't heard, OS X 10.6 Leopard dropped write support for HFS disks and images leaving all of us vintage Mac-ers without the ability to support our habits under Apple's latest equipment. But ...


I was working with Wolf over at LEM's Vintage Mac forum and came up with an extremely simple way to copy HFS disks and images using Terminal. I was using a USB Zip drive, but I would think a USB floppy would work just as well.

Here's the procedure: Unmount the Zip drive using Disk Utility (don't eject), and images. Then type the following commands in Terminal:

Image to Zip:
$ dd if=/Zip.dmg of=/dev/disk2s1

Zip to Image:
$ dd if=/dev/disk2s1 of=/Zip.dmg

Obviously "Zip.dmg" is the name of the disk image. "/Zip.dmg" specifies the image in the root directory or internal hard disk. "disk2s1" is the name of the USB Zip drive. This can be found by mounting the Zip disk and typing $ mount in Terminal. You'll see something like this in the list of reported devices: "/dev/disk2s1 on /Volumes/Untitled (hfs, local, nodev, nosuid, read-only, noowners)" Alternatively, in Disk Utility, you can click on the mounted Zip disk and "Get Info". The first item in the list will be "Disk Identifier : disk2s1" –– Make sure you unmount before you attempt to make a copy. You can do the same thing with the disk images if you don't know where they are and don't want to just put them in the root HD. Just click on the disk image in Disk Utility and look for "Full Path : /Zip.dmg".

ERRORS: I received an Input/Output error report on both making the disks and images, but both seemed to mount and work properly under the OS X Finder as read only. I have not yet tested them with real Macs yet. The disk image attempted to boot under Mini vMac, but reported minor repairs were needed then was unable to create a desktop database. The original disk image from which the real Zip was made and then re-imaged, worked fine in Mini vMac. So I'm not sure what the problem is yet. Also, the blank ZIP disk had already been formatted with HFS standard, so I don't yet know if formatted in another file system (i.e. FAT, HFS+) if this will still work. However, the disk image seems to be a proper HFS image, as Snow Leopard confirms it as read only, and Mini vMac easily reads it, if not able to fully start up from it.

Please, everyone, start trying this with your ZIP and Floppy drives to accumulate some data. There's a solution here somewhere.

Now who wants to write a script to automate this for the rest of us?