FFS compatibility over system versions

[Charles Dickman <chd%chdickman.com@localhost>]

Is the FFS file system compatible over various NetBSD versions? I was
comparing the usability of NetBSD/vax 1.6 vs NetBSD/vax 6.1 on a KA650
and have had some corruption after mounting the same file system under
both versions.

The first indication of a problem was that fsck complained about the
first and second superblocks not matching, but otherwise there were no
problems. I found a reference that said that fsck was broken around
1.6 so I ignored the problem until there was massive file system
corruption.

Now I am not sure if the problem was hardware related or not.

-chuck