term% cat index.txt CFS(4) Kernel Interfaces Manual CFS(4)
NAME
cfs - cache file system
SYNOPSIS
cfs -s [-rd] [-f partition]
cfs -a netaddr [-rd] [-f partition] [mtpt]
DESCRIPTION
Cfs is a user-level file server that caches information about remote
files onto a local disk. It is normally started by the kernel at boot
time, though users may start it manually. Cfs is interposed between
the kernel and a network connection to a remote file server to improve
the efficiency of access across slow network connections such as modem
lines. On each open of a file cfs checks the consistency of cached in‐
formation and discards any old information for that file.
Cfs mounts onto mtpt (default /) after connecting to the file server.
The options are:
s the connection to the remote file server is on file descriptors
0 and 1.
a netaddr
dial the destination netaddr to connect to a remote file server.
r reformat the cache disk partition.
d turn on debugging
f partition
use file partition as the cache disk partition.
All 9P messages except read, clone, and walk (see intro(5)) are passed
through cfs unchanged to the remote server. A clone followed immedi‐
ately by a walk is converted into a clwalk. If possible, a read is
satisfied by cached data. Otherwise, the file server is queried for
any missing data.
FILES
/dev/hd0cache
Default file used for storing cached data.
SOURCE
/sys/src/cmd/cfs
CFS(4)