[...]
Last night, I ran fsck.ext2 from e2fsprogs. I think it took longer than when I ran it under Linux, as it had been running for more than an hour and still hadn’t finished when I went to bed. So I can’t say for certain how long it actually took. Apparently, though, it worked fine, the filesystem was repaired and could delete all under /mnt/datos/COPIA_NETBSD_8I7/*.
Next time (pardon the pun), use `time fsck.ext2 ` so you know how long it took.
This seems to be an endless nightmare: two different operating systems “touching” the same filesystem with different ext2 implementations and possible bugs. Probably not a great idea (I’m the culprit here)....
That's why you need another disk. Format it as ext2 under NetBSD - run your tests. Compare this to your current one, where Linux installed the filesystem and it fails. Cheers