C-Command Software Forum

Error: File exists (-39)

I keep getting this error converting a (large) .dmg file:

hdiutil: unflatten: “<VOLUME>_temp.dmg” failed: File exists (-39)
hdiutil: unflatten failed - error -39
for “<VOLUME>.dmg”

Where <VOLUME> is the name of the imaged volume.

Looking in the hdiutil documentation:

unflatten image
unflatten a UDIF disk image, creating a dual-fork file in tra-traditional
ditional format (resource-only; no XML). If the resource fork
representation of the metadata becomes greater than 16 MB, the
operation will fail with error -39 (“End of fork”).


Any thoughts?



This is a known issue with DropDMG 2.7.9. It should only come into play when converting an existing (very large) image, not when creating a new image. It is only recently that Apple has documented this limitation of the “hdiutil unflatten” command. An upcoming version of DropDMG will include a workaround.

This is fixed in DropDMG 2.8.