hdiutil: convert failed - error -39

[imikey]

I'm unable to backup all the files on one of my volumes because I keep getting the following error:


hdiutil: convert failed - error -39


What does -39 mean?

[dnanian]

Hi, imikey. Unfortunately, Apple has sometimes deigned not to provide us with very useful error messages, and that's a perfect example.

You seem to be backing up to an image: I've seen hdiutil fail when compression is selected in some situations. Try turning compression off, if it's on.

However, it might be better to back up directly to a volume, rather than to an image. Are you backing up to an image for a reason? Would a sparse image, as described here (http://www.shirt-pocket.com/forums/showthread.php?t=81) be an acceptable alternative? It has a lot of advantages...

[imikey]

The reason I like images is because they allow me to store several on the same drive and I like having multiple backups over time. Since Disk Utility never gave me the option of backing up to a volume directly, it never occurred to me to create a sparse image and mount it for the purpose of backing up. That works just as well for my purposes: create a single large sparse image, backup to it weekly using the smart update feature, and then periodically copy the sparse image to offline media.

That's worth the price, so I'll be buying shortly :)

[dnanian]

You've got it exactly. Glad it'll work for you, and thanks for the follow-up.