124 lines
2.1 KiB
Text
124 lines
2.1 KiB
Text
.TH CFS 4
|
|
.SH NAME
|
|
cfs \- cache file system
|
|
.SH SYNOPSIS
|
|
.B cfs
|
|
.B -s
|
|
.RB [ -dknrS ]
|
|
.RB [ -f
|
|
.IR partition ]
|
|
.PP
|
|
.B cfs
|
|
.B -a
|
|
.I netaddr
|
|
.RB [ -dknrS ]
|
|
.RB [ -f
|
|
.IR partition ]
|
|
.RI [ mtpt ]
|
|
.PP
|
|
.B cfs
|
|
.B -F
|
|
.I srvfile
|
|
.RB [ -dknrS ]
|
|
.RB [ -f
|
|
.IR partition ]
|
|
.RI [ mtpt ]
|
|
.SH DESCRIPTION
|
|
.I Cfs
|
|
is a user-level file server that caches data from remote
|
|
files onto a local disk.
|
|
It is normally started by the kernel at boot time, though users may start
|
|
it manually.
|
|
.I 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
|
|
.I cfs
|
|
checks the consistency of cached information and discards any old
|
|
information for that file.
|
|
.PP
|
|
.I Cfs
|
|
mounts onto
|
|
.I mtpt
|
|
(default
|
|
.BR / )
|
|
after connecting to the file server.
|
|
.PP
|
|
The options are:
|
|
.TF -
|
|
.PD
|
|
.TP
|
|
.BI "a " netaddr
|
|
dial the destination
|
|
.I netaddr
|
|
to connect to a remote file server.
|
|
Exclusive with
|
|
.BR -F .
|
|
.TP
|
|
.B d
|
|
turn on debugging.
|
|
.TP
|
|
.BI "f " partition
|
|
use file
|
|
.I partition
|
|
as the cache disk partition.
|
|
.TP
|
|
.BI "F " srvfile
|
|
open
|
|
.I srvfile
|
|
(often a file under
|
|
.BR /srv )
|
|
to connect to a remote file server.
|
|
Exclusive with
|
|
.BR -a .
|
|
.TP
|
|
.B k
|
|
keep cache contents even if they might have come from a different server.
|
|
.I Cfs
|
|
will obey
|
|
.B -r
|
|
even if
|
|
.B -k
|
|
is given.
|
|
.TP
|
|
.B n
|
|
mount the remote file server without authentication;
|
|
often useful with
|
|
.BR -F .
|
|
.TP
|
|
.B r
|
|
reformat the cache disk partition.
|
|
.TP
|
|
.B s
|
|
the connection to the remote file server is on file
|
|
descriptors 0 and 1.
|
|
.TP
|
|
.B S
|
|
turn on statistics gathering. A file called
|
|
.B cfsctl
|
|
at the root of the caching file system can be read to get
|
|
statistics concerning number of calls/bytes on client and server
|
|
sides and latencies.
|
|
.PP
|
|
All 9P messages except
|
|
.BR read ,
|
|
.BR clone ,
|
|
and
|
|
.B walk
|
|
(see
|
|
.IR intro (5))
|
|
are passed through
|
|
.I cfs
|
|
unchanged to the remote server.
|
|
If possible, a
|
|
.B read
|
|
is satisfied by cached data.
|
|
Otherwise, the file server is queried for any missing data.
|
|
.SH FILES
|
|
.TP
|
|
.B /dev/sdC0/cache
|
|
Default file used for storing cached data.
|
|
.SH SOURCE
|
|
.B /sys/src/cmd/cfs
|