Re: [9fans] kfs and cwfs comparison

[erik quanstrom <quanstro@quanstro.net>]

> How about in terms of resources/overhead - is kfs more appropriate in
> constrained/embedded devices than cwfs?

by default, kfs just uses 10mb of memory.  i haven't run cwfs enough to
say with any confidence how well cwfs does.  but kfs will use less disk
space (and if no changes, constant space) since old copies are not kept.

> Or maintainability? Are kfs and cwfs both relatively equal in terms of
> maintenance and/or disaster recovery?

both have a weak spot.
kfs.  there's one copy of the file system.  if you corrupt it, you're out of
luck.  i've never seen this happen.

cwfs.  if the fs is halted during the dump, there is a non-zero chance
of corruption.  i have seen this, but "recover main" can usually roll the
fs back to the last good dump.  the same mechanism can recover a fs
if an untimely shutdown has corrupted the cache.

> Are kfs and cwfs equally dependable/stable?

i would say so.

> Finally, what about the difference between a terminal and auth/cpu/fileserver -
> would kfs/cwfs be more or less appropriate for a terminal vs. a server?

it depends.  i would tend to use kfs only if i were storing my real data
someplace else.  i find the lack of history to be a big problem.  but then
again, i tend not to run fses on terminals.  i just run ken's fs and am done
with it.  :-)

- erik