On Sunday 16 February 2025 22:57:29 Greenwich Mean Time Philip Webb wrote:
> I successfully formatted one of the partitions which failed with Ext2 as
> Vfat. I was able to mount it, create a file with words in it,
> save it, list it via 'ls', browse it & then delete it, all using Gentoo.
> This suggests that the problem isn't due to defective hardware,
> but is somewhere in 'mke2fs' or related material.
> 
> Any observations are very welcome.

A USB drive which disconnects itself without interference by the user does not 
indicate a problem caused by any filesystem in and of itself.

However, a poor quality or buggy USB flash controller which drops the 
connection because it is overloaded by data, could produce all sort of random 
failures.

I am no filesystem expert, but my thinking is an ext2 filesystem will try to 
commit more data to a block device than FAT does while formatted.  Ext2 will 
write in many different blocks across the partition by creating backups of its 
superblock, inode bitmaps, inode tables, etc.  If a USB drive cannot cope with 
this relatively simple transaction of committing to flash cells the structure 
of a filesystem, then it must have bigger problems.

Instead of writing and deleting a simple text file, I would try to stress test 
the drive by copying over a more demanding workload in order to see if this 
succeeds without dmesg coming up with any more errors.