1 .TH VBACKUP 8
2 .SH NAME
3 vbackup, vcat, vftp, vmount, vmount0, vnfs \- 
4 back up Unix file systems to Venti
5 .SH SYNOPSIS
6 .B vbackup
7 [
8 .B -DVnv
9 ]
10 [
11 .B -s
12 .I secs
13 ]
14 [
15 .B -w
16 .I n
17 ]
18 .I disk
19 [
20 .I score
21 ]
22 .PP
23 .B vcat
24 [
25 .B -z
26 ]
27 .I disk
28 |
29 .I score
30 .B >
31 .I disk
32 .PP
33 .B vftp
34 .I disk
35 |
36 .I score
37 .PP
38 .B vmount
39 [
40 .B -v
41 ]
42 .I addr
43 .I mtpt
44 .PP
45 .B vmount0
46 [
47 .B -v
48 ]
49 [
50 .B -h
51 .I handle
52 ]
53 .I addr
54 .I mtpt
55 .PP
56 .B vnfs
57 [
58 .B -LLMRVr
59 ]
60 [
61 .B -a
62 .I addr
63 ]
64 [
65 .B -m
66 .I mntaddr
67 ]
68 [
69 .B -b
70 .I blocksize
71 ]
72 [
73 .B -c
74 .I cachesize
75 ]
76 .I config
77 .SH DESCRIPTION
78 These programs back up and restore standard
79 Unix file system images stored in
80 .IR venti (8).
81 Images stored in
82 .I venti
83 are named by
84 .IR scores ,
85 which consist of a file system type followed
86 by a colon and forty hexadecimal digits, as in:
87 .IP
88 .EX
89 ffs:0123456789abcdef0123456789abcdef01234567
90 .EE
91 .PP
92 (The hexadecimal data is the SHA1 hash of the Venti
93 root block representing the file system image.)
94 .PP
95 These programs expect the environment variable
96 .B $venti
97 to be set to the network address of the Venti server to use
98 (for example,
99 .B yourhost
100 or
101 .BR tcp!yourhost!venti ).
102 .PP
103 .I Vbackup
104 copies the file system stored on
105 .I disk
106 to the Venti server and prints the 
107 score for the newly-stored image.
108 The argument
109 .I disk
110 should be a disk or disk partition device
111 that would be appropriate to pass to
112 .IR mount (8).
113 .PP
114 The optional argument
115 .I score
116 is the score of a previous backup of the disk image.
117 If
118 .I score
119 is given, 
120 .I vbackup
121 will not write to Venti any blocks that have not changed
122 since the previous backup.
123 This is only a speed optimization: since the blocks are already
124 stored on Venti they need not be sent to the Venti server again.
125 .PP
126 The options to
127 .I vbackup
128 are:
129 .TP
130 .B -D
131 .TP
132 .B -V
133 .TP
134 .B -n
135 .TP
136 .B -v
137 .TP
138 .B -w \fIn
139 .TP
140 .B -s \fIsecs
141 .PP
142 .I Vcat
143 writes the named disk image to standard output.
144 Unused file system blocks are printed zeroed regardless
145 of their actual content.
146 .PP
147 If the
148 .B -z
149 flag is given, 
150 .I vcat
151 will attempt to seek over unused blocks instead of writing to them.
152 The
153 .B -z
154 flag should only be used when standard output is seekable
155 .RI ( i.e. ,
156 when it has been redirected to a file or disk).
157 .PP
158 .I Vftp
159 presents the
160 file system image named by
161 .I disk
162 or
163 .I score
164 in a shell-like
165 interactive session.
166 Type
167 .B help
168 at the
169 .B vftp>
170 prompt for details.
171 .PP
172 .I Vmount
173 mounts the NFS service at the network connection
174 .I address
175 onto
176 .IR mountpoint .
177 On most operating systems,
178 .I vmount
179 must be run by the user
180 .BR root .
181 .PP
182 .I Vmount0
183 is a simple C program that 
184 .I vmount
185 uses if 
186 .IR mount (8)
187 does not suffice.
188 .PP
189 .I Vnfs
190 serves, using the
191 NFS version 3 protocol,
192 one or more disk images in a synthetic tree defined
193 by the configuration file
194 .IR config .
195 .I Vnfs
196 announces NFS service at
197 .IR addr 
198 (default
199 .BR udp!*!nfs )
200 and NFS mount service at
201 .IR mntaddr
202 (default
203 .BR udp!*!\fI999 ),
204 registering both with the port mapper.
205 If no port mapper is found running (on port 111),
206 .I vnfs
207 starts its own port mapper.
208 The options are:
209 .TP
210 .B -r
211 Reply to all NFS requests with RPC rejections.
212 .TP
213 .B -M
214 Do not announce an NFS mount service.
215 .TP
216 .B -P
217 Do not register service with the port mapper.
218 .TP
219 .B -a
220 
221 
222 .SH EXAMPLES
223 .PP
224 Back up the file system stored on
225 .BR /dev/da0s1a :
226 .IP
227 .EX
228 % vbackup /dev/da0s1a
229 ffs:0123456789abcdef0123456789abcdef01234567
230 % 
231 .EE
232 .PP
233 Serve that backup and a few others in a tree reminiscent
234 of Plan 9's dump file system, but hide each day's contents of
235 .B /tmp :
236 .IP
237 .EX
238 % cat config
239 mount /2005/0510 ffs:0123456789abcdef\fI...\fP
240 mount /2005/0510/home ffs:0123456789abcdef\fI...\fP
241 mount /2005/0510 ffs:0123456789abcdef\fI...\fP
242 mount /2005/0510/home ffs:0123456789abcdef\fI...\fP
243 hide /*/*/tmp
244 % vnfs -m -b 16k -c 1k config
245 % 
246 .EE
247 .PP
248 Mount the backups on a client machine using
249 .IR vmount :
250 .IP
251 .EX
252 # vmount udp!yourserver!nfs /dump
253 # ls /dump
254 2005
255 # 
256 .EE
257 .PP
258 Mount the backups using the standard NFS mount program:
259 .IP
260 .EX
261 # mount -t nfs -o soft,intr,ro,nfsv3,rsize=8192,timeo=100 \
262 	-o nfsvers=3,nolock,noatime,nodev,nosuid \
263 .EE