if you want to use cwfs as your boot filesystem. i made the program
arguments in a way compatible to kfs so you can put it in your kernel
image as kfs and boot from it. it also doesnt need special
boot/local.c and a loopback network to mount it anymore. for
convinience, i hacked the device string parser to understand file
names as file mapped wren devices so you can directly specify the
plan9 partition path of your configuration device without needing a
map file:
root is from: local!/dev/sdC0/w0
for configuration mode type:
root is from: local!/dev/sdC0/w0 -c
(-c previously ment "use new cache format"... this is reassigned to -C)
my configuration on the thinkpad looks like this:
service cwfs.rei2
filsys main c(/dev/sdC0/w1)f(/dev/sdC0/w0)
filsys dump o
filsys other /dev/sdC0/w2
# w0 - config and fakeworm for main
# w1 - main cache
# w2 - other
alternative syntax for file mapped wren devices is:
w"/foo/bar/baz"
your kernel configuration shoud look like this:
boot
tcp
local
bootdir
bootpcc.out boot
/386/bin/ip/ipconfig
/386/bin/auth/factotum
/386/bin/cwfs kfs
the disadvantage is using cwfs vs fossil is that you cant have
themporary snapshots and here is no temporary flag (chmod -t) per
file. so you have to create your users /tmp in the "other" fs wich
does not get dumped.
/lib/namespace:
# other
mount -qC /srv/boot /n/other other
bind -qc /n/other/usr/$user/tmp /usr/$user/tmp
bind -c /usr/$user/tmp /tmp
also, kenfs/cwfs does a copy on write when changing a already dumped
block in your main filesystem, but new dumped blocks are not
dedublicated by content like in fossil/venti. this means that your worm
may fill up faster than your venti arenas would.
filesystem limitations like filename length and maximum file size is
fixed once you created your filesystem. the maximum filename length
is smaller than fossils, so you may want change that in the
configuration and recompile before creating your filesystem.
but on the good side kenfs/cwfs is a lot simpler in its design and
implementation than fossil/venti. its working pretty robust for me
since i switched. no bad surprises yet.
--
cinap
--- Begin Message ---
Is Fossil (with Venti) the only filesystem which provides daily
snapshots? I've been meaning to ask this for some time.
--
Simplicity does not precede complexity, but follows it. -- Alan Perlis
--- End Message ---
