I have a 2TB external drive for time machine backups; system reported an error so I tried running Disk Utility. Unmounted successfully, got to checking catalog and stopped there. At least stopped for the past hour. Do I just let it keep trying, or what? How do I exit if so? imac 2012 running Catalina. Drive is WD My Passport 2TB
iMac Line (2012 and Later)
It took several hours for me to run First Aid on my TM drive due to the complex ecosystem of permissions and hard links. Let it go overnight.
There could be two problems with the drive:
(1) File catalog error. This can be fixed by erasing and reformatting, which of course means you lose all the data on the drive. You can also try to copy everything from the drive first but the integrity of the device (and its contents) is in question. Even if you do manage to copy some or all files, it won't be usable as a Time Machine backup, more like a partial archive as of today.
(2) Physical hardware anomaly on the drive. This could have caused (1), and if the hardware is compromised, yes, you have no choice but to dispose of the drive. You can download DriveDX and check the physical integrity of the drive with that.
I would no longer trust the device anyway, a backup must be reliable. All drives wear out or stop working eventually, they have many moving mechanical parts -- unless they are SSDs, but they wear out eventually also.
I would dispose of the questionable drive and procure two new external drives, use them both as Time Machine drives. Time Machine will use both and alternate between them, each will keep a full and complete standalone backup of your main drive if used that way. Then if one of the Time Machine drives becomes unreliable, you will still have a working backup.
Time Machine backup drives file structures are much more complex than an ordinary drive. I would let it run overnight at least, presumably you have since I noticed your original post was yesterday.
Hi there bennetts,
Thanks for reaching out to Apple Support Communities. We understand you're attempting to run First Aid on your external drive and would be happy to provide you with some more information. Factoring in the size of your external drive along with the age of your Mac, it may be expected behavior for this process to take an extended amount of time. We'd recommend continuing to wait for this process to complete. The support article below will also provide you with some additional information on the repair process in Disk Utility.
Repair a storage device in Disk Utility on Mac
Best regards.
I did indeed let it run and sure enough, it finally kicked out some more info. Unfortunately, not what one would have hoped for, however. Here's what it says now:
Running First Aid on “BlueWD” (disk3s3)
Repairing file system.
Volume is already unmounted.
Performing fsck_hfs -fy -x /dev/rdisk3s3
Checking Journaled HFS Plus volume.
Checking extents overflow file.
Checking catalog file.
Invalid node structure
Invalid sibling link
Rebuilding catalog B-tree.
Disk full error
The volume BlueWD could not be repaired.
File system check exit code is 8.
Restoring the original state found as unmounted.
File system verify or repair failed. : (-69845)
Operation failed…
So, what next? WD support says it's dead and I should just chuck it, which is certainly an option, but I hate to lose all that backup history, not to mention the cost of replacement, unless I truly have to.
Disk utility stuck on checking catalog?
