I'm looking for interested volunteers to test automated fixing of the
botched ffs1 superblock problem.  Specifically,  I would like
additional testing of using fsck_ffs -c3 to downgrade a fslevel 4
filesystem to an fslevel 3 filesystem which can be used on 1.6.2

Addtionally, to support users who desire to upgrade their systems
without console access, I have provided an rc.d script in
src/etc/rc.d/fixsb which will automatically discover and fix the
botched superblock problem on boot by running both
  fsck_ffs -p -b16 -c4
  fsck_ffs -p -c3
on affected filesystems.  This script is currently untested
and would benefit from some workout before it is enabled
in any non-console upgrade.

Please report bugs related to this issue to NetBSD pr 25138.

Thanks,
Darrin