Unable to restore unindexed data on external hard drive with Apple Disk Utility

7 TB is a lot of data. Proceed cautiously and think everything through before doing anything. I am almost afraid to ask: is this data backed up? It's important to back up anything important. There are automated programs that will do this (including Apple's free Time Machine).

It sounds like possibly the drive was forcibly ejected due to the cable dislodgment and since it was in the middle of modification to the file system, the file system (catalog) MIGHT have been corrupted.

If the external drive is HFS+, I would suggest looking seriously at Disk Warrior. One problem with file system repair tools is if they don't work, one can create additional damage or even make the entire disk unrecoverable, a total loss.

Disk Warrior is a bit different. It recreates the entire file system from scratch. This can take a long time (especially for 7 TB), because this is analogous to driving up and down every street in a city and re-recording where every house and address is located. And imagine each house is actually in pieces in different parts of the city. That is what hard drives are like. But Disk Warrior does not try to "repair" the file system, it recreates the entire thing. After it completes this task, it presents you with a listing of files and folders as indicated under the existing file system, and side by side shows the new candidate file system it presents for you to approve. Only after you approve the new result, does it actually go and replace the old one. "DiskWarrior's patented preview feature lets you see how your disk will appear after it is repaired, but before any changes are made. You can even compare your disk in its damaged state to its repaired state." Then, if you choose to proceed (and if you have concerns you can simply say "no" and then no changes are applied), Disk Warrior claims it uses a "fail safe" method to replace the old with the new file system, although I don't know what that "fail safe" claim means exactly, I think it uses a method that is resilient to loss of power during the process, for instance.

I have Disk Warrior but have not needed to use it for years. However when I did use it, it restored a drive that was completely unusable, not one single file could be retrieved, and afterwards it was all back, 100%. So I know that under some circumstances it can work very well. When it works like this, it is truly like black magic when it restores an entire drive. But if there is hardware damage, none of these utilities may work.

If the external drive is a spinning mechanical drive, there are some very expensive things you can try that may work. Recovery companies will take the platters apart and try to read all the individual bits (ones and zeroes) off the platters. This is expensive because it is done in clean rooms and very labor intensive. With 7 TB of data, it will be very costly, possibly many thousands of $. What is recovered might be fragments of files. Probably only to be pursued if the data lost is priceless and you have to have whatever can be salvaged.

P.S. I would contact Sandisk because they may have proprietary recovery software that works better with their hardware. They do have such tools for their camera cards.

Quillnib wrote:

The USB-C cable connecting my MacBook Pro to my Sandisk external hard drive spontaneously disconnected while I was rendering in Final Cut Pro. I tried using the Disk Repair setting without success.

Should I try using Disk Warrior. It says that it is compatible with Ventura 13 for repairing external drives. As we are now at Ventura 13.4, am I correct in assuming there is no point in going down this route until Disk Warrior updates their software?

How is the external drive formatted...?

I suspect when Disk Warrior says <Ventura 13 > it is inclusive of subsequent point updates .

But I have zero experience with it working on APFS drives—which is still an issue for DIskUtility.app

you can reach out to DW support

https://www.alsoft.com/support-diskwarrior-5

Quillnib wrote:

Drill Disk claims in the App Store that they can retrieve files and restore indexing, but I am going to hold off on trying that until I hear back from Sandisk, just in case Drill Disk further damages the indexing.

You mention "indexing" several times. Is your disk working properly? Indexing normally happens as a background process. Utilities like Apple's Disk Utility, Disk Warrior, Tech Tool Pro, Disk Drill etc. work to try to recover or repair the file system, which is not the same as "indexing." Files are physically stored in fragments across a Mac disk; the file system is the map that indicates where a file's fragments are physically located so the file can be put together and accessed. If the file system is damaged, that map doesn't work anymore. Some utilities try to repair the file system (map); others, like Disk Warrior, recreate the entire file system from scratch. Different utilities use different methods, so sometimes one will work when the others don't.

If you can mount the external drive and see files, you should copy them all off as soon as possible. Then you can format/erase the drive and copy the files back.

Some of these utilities offer a free limited functionality version that lets you see if files can be recovered at all, before you buy the tool.

"the gravitational pull of the chord loosened the USB-c cable and caused Hard Drive to be disconnected. "

If this means the HDD fell and hit the floor, it's likely damaged. I've accidentally disconnected plenty of drives over the years; I've never had a simple disconnection damage a drive to the point it would no longer work. But a hard fall can easily damage an HDD.

There are file restoration apps out there, but they are commonly used to recover deleted files. If the data and/or drive is damaged, that's not just a simple deletion reversal.

With APFS I do not know of anything that works quite the same way as Disk Warrior.

Tech Tool Pro, Disk Drill, and some others claim to be able to repair APFS drives. But there is so little documentation out for APFS, it's hard to see how they develop these utilities.

Disk Warrior can repair damaged external drives as long as they are HFS+. If they are APFS, Disk Warrior cannot repair them. Disk Warrior works under Ventura.