strange file copying error - Mac OS Sonoma 14.5

[nickyr]

hello

while recently copying a folder from one external drive to another (both plugged into the same hub and both connected over Thunderbolt 4), at the end of the process I got a message saying the target drive "disappeared" and the copy could not be completed.

I then copied things folder by folder until I found the problem folder, and then file by file until I found the problem file (a tiff image).

anyway, after re-connecting the same source drive to the same target drive using the same hub again, only this time via a USBA port on it, it copied over with no issue. I even used the same TB4 cable only with a USBA adapter on one end.

I can't understand why the file would be OK to copy over TB4 to USBA but not TB4 to TB4.

Any ideas / suggestions?

thanks as always, Nick

 

[MacInWin]

Well, since the only thing that changed was the port, it would appear that the particular port on the hub is not providing the power to run the drive properly, so it "disappears" from the system. Either that, or the port has a data issue as well that is causing it to appear to "disappear." Either way, the most likely culprit is the port.

I've never seen a drive disappear while in use like that. Very strange.

 

[ferrarr]

Is it an A/C powered hub, or a USB powered hub? Sometimes if both devices draw too much power from a USB powered hub, this will be the issue.

 

[nickyr]

I thought that too. But in my testing it copied everything absolutely fine until this one file. I tried it at the start of a sequence of copies, at the end and in the middle. It was always this one file that caused the "disappearance". Bizarre indeed!

It's a powered hub.

 

[MacInWin]

Is the file very big? I wonder if a long read/write sequence is overheating the destination and it "disappears" because of the heat.

 

[MacInWin]

To be honest, the fact that the "disappearing" is associated with one file is very strange. I have seen errors on file transfers, of course, and I have seen disappearing drives, but never have the two been linked. File copy errors are normally because of bad sectors or bad blocks where the data is corrupted and disappearing drives are normally either power or intermittent connection issues, but to have a reproduceable disappearing drive with ONE file is kind of hard to imagine.

Are these two drives SSDs or HDs?

 

[nickyr]

I'm copying from a Samsung T7 external SSD to an NVME drive in an enclosure. There is plenty of room on both.
The strangest thing is the file will copy absolutely fine if I plug it into a USBA port, but not a TB one. The recipient drive doesn't get hot and I can remount it and copy other files straight away with no issues.

The file is around 1GB, but larger, same format tiff files were copied again with no issues - just this one file that was a problem. It's not corrupted as I can open it both on the source and copy drive. it's a real head scratcher!

 

[pm-r]

just this one file that was a problem.

Did you have a look in your Console log just in case it may provide some sort of hint or suggestion of what might have gone wrong or if it even noticed anything was wrong.

Just to remote on chance it might list something you could use to save getting slivers scratching your head.

But computers can make mistakes and do odd things occasionally. It's amazing they work as well and as accurately as they do, especially at the speeds they do what they do these days.


I guess it's a good thing that you were alerted that there was a problem. Otherwise you could have missed noticing the error.




- Patrick
=======

 

[Jimmysb]

I have had similar experiences on Windows PCs, and like you by coping folder then file found the 'guilty' file(s) (not always a single file). Even after 40 years with computers, I just put it down to "one of those things", life is (now) too short to worry or even worse become almost paranoid over these type of incidents.

 

[nickyr]

thanks everyone
I'll chalk it down to experience and keep an eye out in case it happens again. certainly a strange one though!