I have a 2TB external hard drive that no longer appears in Finder, though it still shows up in Disk Utility. It’s full of videos and photos, and I’m attempting to back it up to another external drive, then wanna recover files from it.
Here’s what I did: in Disk Utility, I created a new image of the failing drive and saved it as a read/write DMG file on a different external hard drive. The imaging process worked, but when I try to open the DMG with DiskImageMounter, it gets stuck on “Verifying” and won’t mount.
Is there a way to skip verification or use another tool to get into the DMG and recover my files?
I’d suggest running First Aid on the original external drive again before creating another image.
If First Aid fails, try imaging it in read-only mode instead of read/write.
Sometimes read/write adds extra verification steps that break when the drive has errors. Then you’d better use some NTFS drivers for Mac like iBoysoft NTFS for Mac to enable read and write.
I ran into the same problem before. DiskImageMounter tends to choke on damaged or huge DMGs. Instead of double-clicking it, try opening Disk Utility > File > Open Disk Image and mount the DMG from there. Sometimes it’ll bypass the endless “verifying” loop.
If the drive can’t be accessed on multiple Macs, unfortunately it could mean the drive is failing or already failed.
That said, there are a few third-party utilities that may still help recover your data as long as the drive is visible in Disk Utility or Terminal. Examples include iBoysoft Data Recovery for Mac.
How about the command hdiutil attach -nomount /path/to/your.dmg in Terminal?
Honestly, if the data is super important (family photos, videos, etc.), I’d stop trying to mount the DMG and run a data recovery program (like iBoysoft Data Recovery) directly on the failing external drive. DMGs are just clones of the errors, so recovery software might have a better chance of grabbing the files.