Unable to mount older NDIF .img's - please advise

Hi, Cindy. Welcome to the Discussions.

1. You wrote:

"then comes the error message."

What is the exact text of the error message?

2. A reading of the man (manual) page for the hditutil command, under the discussion of the convert verb, indicates that all NDIF image formats except the Disk Copy 6.3.3 format have been deprecated, i.e. are considered obsolete and support for them will be withdrawn entirely at some future time. That support may have already been withdrawn from Disk Utility.

3. There are no third-party utilities that can convert or mount NDIF images. This is because they used a proprietary, Apple-only compression scheme. See the section entitled "New Disk Image Format" in this document.

4. How comfortable are you using Terminal? I ask because it may be possible to convert the NDIF images to a supported, current format that can be mounted using the convert verb of hditutil. The general syntax of the command would be:

hdiutil convert /pathtoNDIF -format UDRO -o ~/Desktop/newname

where:

• hdiutil is the command

• convert is the verb: we want hdiutil to convert the image to another disk image format.

• /pathtoNDIF is the directory path to one of the NDIF images you want to convert.

• -format is an option of the convert verb, specifying that the next string will be the new format.

• UDRO is the new format: UDIF Read-Only disk image, i.e. a Read-Only disk image from which you can copy the files it contains.

• -o is an option of the convert verb, specifying that the next string will be the path for saving the converted disk image.

• ~/Desktop/newname specifies that the converted image should be saved to a disk image with file name newname on your desktop. If newname is to contain spaces, the easiest way to handle this is to include all of ~/Desktop/newname in double-quotes.

The entire command is typed as a single line: stretch your browser window to see this if the text is wrapped when reading this post.

For example, if you had one of the NDIF files on your desktop and its file name was OldDocs.img, you could convert this to a currrent Read-Only disk image format with the single command:

hdiutil convert ~/Desktop/OldDocs.img -format UDRO -o ~/Desktop/New_OldDocs

which will create New_OldDocs.dmg on your desktop. Double-clicking New_OldDocs.dmg should result in it being mounted so you can then copy the files from such if desired.

Good luck!

😉 Dr. Smoke
Author: Troubleshooting Mac® OS X

The images might be unusable - that would depend on their history with respect to how they were backed up and subsequently copied. If the disk image file's forks have been split on a pre-OS X system, and both parts are still together, then I don't know of a way to reconstitute them in OS X but a computer running OS 9 should have no problem with them at all.

" I copied my NDIF .img to the desktop, it's name is Organix.img, so I changed your code to:"

In the example with the "Organix.img" file, if the problem is split forks, since the file was copied to the "Desktop", I would suspect that that copy operation did not include the resource component so that copy of the file is likely to be corrupt. One way to check if it has anything in its resource fork is to issue this command:<pre>cat -v ~/Desktop/Organix.img/..namedfork/rsrc</pre>The presence of output doesn't necessarily mean that the file contains the resources required to make the ".img" file readable, but the absence of output is a sure sign that its resource fork is empty.

I think it is important to go back to the original backup media. At the very least, don't move individual files around because the resource fork data were stored in the same folder as the original file in an invisible folder called "RESOURCE.FRK" (the resources for a given file were contained in that folder, and had the same name as the file except in "all-caps" or truncated with a "~" for names longer than 8 characters). If that arrangement is not preserved, then it probably won't be possible to access the file. Spotlight may be able to find items whose name is "RESOURCE.FRK" and whose visibility corresponds to "invisible items" so check the directories containing the backups for the presence of that folder and the corresponding files. If they are there, then try to find a machine booted in OS 9 (not "OS X" running "Classic") on which to open them. Then copy the files or the disk image to an "HFS+" formatted disk for use on "OS X".

I suspect that the problem isn't that OS X can't mount the NDIF, but rather the method used to back up the files. Old style NDIF disk images are of a "dual fork format" meaning they have a "resource fork". If such an image was backed up to a volume that wasn't "Mac" formatted (ie. something other than HFS+ or HFS), the file would have had to have been split into separate "data" and "resource" forks. This is still true for files with resource forks in "OS X", but the method used to store the resource fork is different between OS X and pre-OS X systems, and unfortunately, "OS X" (including "Classic" under "OS X") can't seem to recognize the old method (and vice-versa).

So if the files were backed up to a dos-formatted disk or a CD, and the files are still on the original media to which they were backed up, it should be possible to access them from a machine that is booted in "OS 9". It should then be possible to copy them to an HFS+ formatted disk for transfer to "OS X". If there isn't a pre-OS X machine available, I'm not sure what options are available to reassemble in files split by System 9 directly in "OS X.

However, if the files at any time were copied using "OS X" or Windows, then there's a chance that the file containing the "resource fork" may have been left behind. In this case, the file may be irreversibly damaged.

I suppose it wouldn't hurt to try 'hdiutil' but "DiskImageMounter.app" in "OS X" should be able to open "Disk Copy" images, at least back to version 4.2 (circa System 7.5.3; maybe earlier). The fact that it tried and failed makes me suspect that something is wrong with the images themselves.

Hi, biovizier.

I agree with your potential assessment, though I started my long reply before you posted, broke for brunch, and finished up thereafter, hence the timing of our respective posts. It certainly wouldn't hurt to try, and why I suggested it. A "Hail Mary" pass given Cindy's predicament and I didn't want to panic her right off with the possibility that the files could be corrupted, as you suggest, before giving her a chance to try hdituil.

Good luck!

😉 Dr. Smoke
Author: Troubleshooting Mac® OS X

Hi, Cindy.

Yes, you copied it correctly and your changes look right based on the info you provided.

Could be that biovizier's suspicion is correct, meaning the images are unusable.

You might want to try a couple of the other images.

Good luck!

😉 Dr. Smoke
Author: Troubleshooting Mac® OS X