Re: [9fans] 9front: /lib/ndb/local clobbered after edit w/ sam, soon following update

[cinap_lenrek@felloff.net]

sounds like filesystem corruption, yes. in that case, do not override
anything. keep it as it is and depending on the filesystem, run a check
to determine the extend of the damage.

what filesystem is this? if its cwfs, read further:

if the damage seems small, you might just clear the directory entry
for the corrupted files (abandoning the blocks) and recreate it from
backup. do not just delete the file or override it! the block pointers
could be wrong pointing into other files, you'll just corrupt these
or put these blocks on the freelist! a filesystem check can reveal this.

see fs(8) manpage for the check and clri commands.

you enter these commands on the filesystem console, accessube by:

con -Cl /srv/cwfs.cmd

with cwfs, all changes to the filesystem are first done in the cache
and later the cache is written out to the dump at night. you can
recover main from the worm dump, which will reinitialize the cache.

note, this assumes that the corruption is in the cache only and hasnt
propagated to the worm yet. (check 9fs dump; cd /n/dump and see
if the backup is still intact)

to reinitialize the cache from last dump, you reboot and
use bootargs local!/dev/sdXX/fscache -c to enter config mode,
then in config mode enter:

recover main
end

--
cinap