Can't mount external drive. Can't fix either

[dfelix]

Hi,

My external drive won't mount. When I try to run disk utility reoair, it gives me as follows:

Repairing file system.
Volume is already unmounted.
Performing fsck_hfs -fy -x /dev/rdisk4s2
File system check exit code is 8.
Restoring the original state found as unmounted.
File system verify or repair failed.

Operation failed…

How can I fix this to mount my drive?

Thanks.
[doublepost=1561064284][/doublepost]rdisk4
rdisk4s1
rdisk4s2
rdisk4s3

Are the volumes on rdisk4 apparently. It's one big 3TB HFS volume. I assume the others are helper partitions.
[doublepost=1561065070][/doublepost]

 

[HDFan]

Here's an older post with some suggestions:

https://forums.macrumors.com/threads/file-system-check-exit-code-8-disk-wont-repair.1819660/

 

[Fishrrman]

Can the drive be mounted on OTHER Macs?

Try this.
Sometimes it works, then again, maybe not.
Trying it WON'T HURT ANYTHING:
1. Power down, all the way off
2. DISCONNECT the external drive
3. Power up the Mac, get to the finder.
4. NOW connect the external drive.
5. IF the drive icon doesn't appear.... just... wait... for a while.
6. Let it sit for up to an hour or so.

WHY I'm asking you to try this:
Now and then the finder (when it can't mount a drive easily) will attempt its own routines to try to "repair" it.
Sometimes this works with a drive or partition that won't mount.
Again, no promises.

 

[hobowankenobi]

Click on view just above the drive icons and change it to see drives and volumes. Gives a bit more insight. Hate that Apple make the default "hide".

If repeated attempts won't repair either the drive or individual partitions, you can try some CLI to see if you get better results. More clues here.