transient corruption when reading files on external APFS drive

I am experiencing occasional corrupted data when reading files on an external hard drive using an APFS volume running 10.14.2. The errors are not strictly repeatable, but they often involve the same or similar files.

It took some doing, but I now have copies of a file with both the correct and the corrupt contents.

The files have the same length.

The corrupted file contains a repetition of previously read data at one point and slightly later an omission of the same amount of data, which is 12288 bytes (3 x 4096).

Is this more likely to be a disk drive problem, a Firewire 800 problem, or an APFS problem?

How might I figure this out?

Replies

Not sure this is a devForums question. Can you talk about the macOS application you're trying to build?