It appears that after a recent update, the drive is experiencing difficulty mounting consistently. Despite showing up in Disk Utility after a delay, it take ages to mount when plugged in. then I can't read or write any data The drive is also visible in Terminal.
I have attached some screen shots I hope some one can help :)
[Re-Titled by Moderator]
Mac mini (M2 Pro, 2023)
That drive is failing. It has over 1K sectors pending reallocation which is a lot. You are not going to be able to read from that drive since it will be throwing a lot of errors. It is time to retire that drive.
If the drive is still under warranty, then you should be able to get a warranty replacement for it. Just mention the number of Sectors Pending Reallocation as justification (and possibly the SMART failure status caused by the Raw Read Error Rate of attribute#1). If it is covered by warranty, then make sure to attempt to securely erase the drive by writing zeroes to the whole drive. You probably won't be able to do this with macOS....the G Drive does not need to be mounted in order to write zeroes to it. You can try using Disk Utility and its secure erase option, but I think you will have much better luck using "dd" on the command line or connecting the drive to a Linux system (even Windows would probably be better than macOS to do the secure erase...there is even a special bootable ShredOS USB stick that can be used on a standard Intel/AMD system).
If you need to recover data from this drive because you do not have a backup of that data, then contact a professional data recover service to get an estimate. Normal utilities (even data recovery utilities) will not help here because they are unable to deal with the errors thrown by the failing drive....they will just make the failure even worse. Even macOS will get in the way and make things worse.
FYI, the macOS update did not cause this problem. This is a hardware failure of the drive caused by bad spots on the drive platters.
That drive is failing. It has over 1K sectors pending reallocation which is a lot. You are not going to be able to read from that drive since it will be throwing a lot of errors. It is time to retire that drive.
If the drive is still under warranty, then you should be able to get a warranty replacement for it. Just mention the number of Sectors Pending Reallocation as justification (and possibly the SMART failure status caused by the Raw Read Error Rate of attribute#1). If it is covered by warranty, then make sure to attempt to securely erase the drive by writing zeroes to the whole drive. You probably won't be able to do this with macOS....the G Drive does not need to be mounted in order to write zeroes to it. You can try using Disk Utility and its secure erase option, but I think you will have much better luck using "dd" on the command line or connecting the drive to a Linux system (even Windows would probably be better than macOS to do the secure erase...there is even a special bootable ShredOS USB stick that can be used on a standard Intel/AMD system).
If you need to recover data from this drive because you do not have a backup of that data, then contact a professional data recover service to get an estimate. Normal utilities (even data recovery utilities) will not help here because they are unable to deal with the errors thrown by the failing drive....they will just make the failure even worse. Even macOS will get in the way and make things worse.
FYI, the macOS update did not cause this problem. This is a hardware failure of the drive caused by bad spots on the drive platters.
So this G Drive was working fine until you installed a macOS update?
Was this a minor point release update such as 14.1 to 14.4, or was a major OS upgrade from 13.x to 14.4?
Are you using the manufacturer's proprietary software to manage this G Drive? If so, did you use that software to enable full disk encryption on the drive? If so, then you may need to see if there is an update to that proprietary software since the old version may no longer be compatible with the updated OS.
Run DriveDx (free trial period) and post the complete text report here using the "Additional Text" icon which looks like a piece of paper on the forum editing toolbar. You will need to install a special USB driver in order to attempt to access the health information on the external drive. First thing is to make sure this G Drive appears to be physically healthy.
What file system was on this G Drive?
Is this G Drive used with any other computers?
Refer back to your First Image
It is showing the Partition Map is " Not Supported "
Not sure what Partition Map was on the drive previous to the " recent update "
I have run Drive DX here is the full report
I am unable to mount External HD on my Mac mini with macOS Ventura
