Subversion Repositories planix.SVN

Rev

Rev 2 | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
2 - 1 
.TH RAMFS 4
2 
.SH NAME
3 
ramfs  \- memory file system
4 
.SH SYNOPSIS
5 
.B ramfs
6 
[
7 
.B -Dipsu
8 
]
9 
[
10 
.B -m
11 
.I mountpoint
12 
]
13 
[
14 
.B -S
15 
.I srvname
16 
]
17 
.SH DESCRIPTION
18 
.I Ramfs
19 
starts a process that mounts itself (see
20 
.IR bind (2))
21 
on
22 
.I mountpoint
23 
(default
24 
.BR /tmp ).
25 
The
26 
.I ramfs
27 
process implements a file tree rooted at
28 
.IR dir ,
29 
keeping all files in memory.
30 
Initially the file tree is empty.
31 
.PP
32 
The
33 
.B -D
34 
option enables a trace of general debugging messages.
35 
.PP
36 
The
37 
.B -i
38 
flag tells
39 
.I ramfs
40 
to use file descriptors 0 and 1 for its communication channel
41 
rather than create a pipe.
42 
This makes it possible to use
43 
.I ramfs
44 
as a file server on a remote machine: the file descriptors 0
45 
and 1 will be the network channel from
46 
.I ramfs
47 
to the client machine.
48 
.PP
49 
The
50 
.B -p
51 
flag causes
52 
.I ramfs
53 
to make its memory `private'
54 
(see
55 
.IR proc (3))
56 
so that its files are not accessible through the debugging interface.
57 
.PP
58 
The
59 
.B -s
60 
.RB ( -S )
61 
flag causes
62 
.I ramfs
63 
to post its channel on
64 
.B /srv/ramfs
65 
.RB ( /srv/ \fIsrvname\fR)
66 
rather than mounting it on
67 
.IR mountpoint ,
68 
enabling multiple clients to access its files.
69 
However, it does not authenticate its clients and its
70 
implementation of groups is simplistic, so
71 
it should not be used for precious data.
72 
.PP
73 
The
74 
.B -u
75 
option permits
76 
.I ramfs
77 
to consume as much memory as needed;
78 
without it,
79 
.I ramfs
80 
will limit its consumption to some arbitrary amount,
81 
currently 768MB (enough to hold a CD image).
82 
.PP
83 
This program is useful mainly as an example of how
84 
to write a user-level file server.
85 
It can also be used to provide high-performance temporary files.
86 
.SH SOURCE
87 
.B /sys/src/cmd/ramfs.c
88 
.SH "SEE ALSO"
89 
.IR bind (2)