3 405d555f 2008-06-14 rsc vac, unvac \- create, extract a vac archive on Venti
4 058b0118 2005-01-03 devnull .SH SYNOPSIS
13 058b0118 2005-01-03 devnull .I blocksize
16 058b0118 2005-01-03 devnull .I oldvacfile
19 058b0118 2005-01-03 devnull .I exclude
22 058b0118 2005-01-03 devnull .I vacfile
31 e05b0ff3 2008-07-03 rsc .I excludefile
33 058b0118 2005-01-03 devnull .I file ...
46 058b0118 2005-01-03 devnull .SH DESCRIPTION
48 058b0118 2005-01-03 devnull creates an archival copy of Plan 9 file trees on Venti. It can be used
49 058b0118 2005-01-03 devnull to build a simple backup system. One of the unusual properties of Venti is
50 058b0118 2005-01-03 devnull that duplicate blocks are detected and coalesced. When
52 058b0118 2005-01-03 devnull is used on a file tree that shares data with an existing archive, the consumption of
53 058b0118 2005-01-03 devnull storage will be approximately equal to an incremental backup.
54 058b0118 2005-01-03 devnull This reduction in storage consumption occurs transparently to the user.
56 058b0118 2005-01-03 devnull As an optimization, the
60 058b0118 2005-01-03 devnull options, described below, can be used to explicitly create an archive relative to an existing archive.
61 058b0118 2005-01-03 devnull These options do not change the resulting archive generated by
62 058b0118 2005-01-03 devnull .IR vac ,
63 058b0118 2005-01-03 devnull but simply reduce the number of write operations to Venti.
65 058b0118 2005-01-03 devnull The output of
67 405d555f 2008-06-14 rsc is the hexadecimal representation of the SHA1 fingerprint of the root of the archive, in this format:
70 058b0118 2005-01-03 devnull vac:64daefaecc4df4b5cb48a368b361ef56012a4f46
73 405d555f 2008-06-14 rsc The options are:
75 e05b0ff3 2008-07-03 rsc .BI -a " vacfile
76 e05b0ff3 2008-07-03 rsc Specifies that vac should create or update a backup archive, inserting
77 e05b0ff3 2008-07-03 rsc the files under an extra two levels of directory hierarchy named
79 e05b0ff3 2008-07-03 rsc (year, month, day)
80 e05b0ff3 2008-07-03 rsc in the style of the dump file system
81 e05b0ff3 2008-07-03 rsc (see Plan 9's \fIfs\fR(4)).
84 e05b0ff3 2008-07-03 rsc already exists, an additional backup day is added to the
85 e05b0ff3 2008-07-03 rsc existing hierarchy, behaving as though the
87 e05b0ff3 2008-07-03 rsc flag was specified giving the most recent backup tree in the archive.
88 e05b0ff3 2008-07-03 rsc Typically, this option
89 e05b0ff3 2008-07-03 rsc is used as part of a nightly backup script.
90 e05b0ff3 2008-07-03 rsc This option cannot be used with
95 058b0118 2005-01-03 devnull .BI -b " blocksize
96 058b0118 2005-01-03 devnull Specifies the block size that data will be broken into.
97 058b0118 2005-01-03 devnull The units for the size can be specified by appending
99 058b0118 2005-01-03 devnull to indicate kilobytes.
100 058b0118 2005-01-03 devnull The default is 8k.
101 058b0118 2005-01-03 devnull The size must be in the range
102 058b0118 2005-01-03 devnull of 512 bytes to 52k.
104 058b0118 2005-01-03 devnull .BI -d " oldvacfile
105 058b0118 2005-01-03 devnull Reduce the number of blocks written to Venti by comparing the files to be stored with
106 058b0118 2005-01-03 devnull the contents of an existing
108 a7f1ab29 2011-05-10 rsc file tree whose score is stored in
109 058b0118 2005-01-03 devnull .IR oldvacfile .
111 058b0118 2005-01-03 devnull .BI -e " exclude
112 058b0118 2005-01-03 devnull Do not include the file or directory specified by
113 058b0118 2005-01-03 devnull .IR exclude .
114 058b0118 2005-01-03 devnull This option may be repeated multiple times.
116 e05b0ff3 2008-07-03 rsc can be a shell pattern as accepted by
118 e05b0ff3 2008-07-03 rsc with one extension:
120 e05b0ff3 2008-07-03 rsc matches any sequence of characters including slashes.
122 058b0118 2005-01-03 devnull .BI -f " vacfile
123 058b0118 2005-01-03 devnull The results of
125 a7f1ab29 2011-05-10 rsc are placed in
126 058b0118 2005-01-03 devnull .IR vacfile ,
127 058b0118 2005-01-03 devnull or the standard output if no file is given.
129 058b0118 2005-01-03 devnull .BI -i " name
130 058b0118 2005-01-03 devnull Include standard input as one of the input files, storing it in the archive
131 058b0118 2005-01-03 devnull with the specified
132 058b0118 2005-01-03 devnull .IR name .
134 058b0118 2005-01-03 devnull .BI -h " host
135 058b0118 2005-01-03 devnull The network address of the Venti server.
136 058b0118 2005-01-03 devnull The default is taken from the environment variable
137 058b0118 2005-01-03 devnull .BR venti .
138 058b0118 2005-01-03 devnull .\" If this variable does not exist, then the default is the
139 058b0118 2005-01-03 devnull .\" metaname
140 058b0118 2005-01-03 devnull .\" .BR $venti ,
141 058b0118 2005-01-03 devnull .\" which can be configured via
142 058b0118 2005-01-03 devnull .\" .IR ndb (6).
145 058b0118 2005-01-03 devnull Expand and merge any
147 058b0118 2005-01-03 devnull archives that are found while reading the input files. This option is
148 058b0118 2005-01-03 devnull useful for building an archive from a collection of existing archives. Each archive is inserted
149 058b0118 2005-01-03 devnull into the new archive as if it had been unpacked in the directory in which it was found. Multiple
150 058b0118 2005-01-03 devnull archives can be unpacked in a single directory and the contents will be merged. To be detected, the
151 058b0118 2005-01-03 devnull archives must end in
152 058b0118 2005-01-03 devnull .LR .vac .
153 058b0118 2005-01-03 devnull Note, an archive is inserted by simply copying the root fingerprint and does not require
154 058b0118 2005-01-03 devnull the archive to be unpacked.
157 058b0118 2005-01-03 devnull Increase the performance of the
161 e05b0ff3 2008-07-03 rsc options by detecting unchanged files based on a match of the files name and other meta data,
162 058b0118 2005-01-03 devnull rather than examining the contents of the files.
165 058b0118 2005-01-03 devnull Print out various statistics on standard error.
168 058b0118 2005-01-03 devnull Produce more verbose output on standard error, including the name of the files added to the archive
169 058b0118 2005-01-03 devnull and the vac archives that are expanded and merged.
171 e05b0ff3 2008-07-03 rsc .BI -x " excfile
172 e05b0ff3 2008-07-03 rsc Read exclude patterns from the file
173 e05b0ff3 2008-07-03 rsc .IR excfile .
174 e05b0ff3 2008-07-03 rsc Blank lines and lines beginning with
176 e05b0ff3 2008-07-03 rsc are ignored.
177 e05b0ff3 2008-07-03 rsc All other lines should be of the form
182 e05b0ff3 2008-07-03 rsc .I pattern .
183 e05b0ff3 2008-07-03 rsc When considering whether to include a directory or file
184 e05b0ff3 2008-07-03 rsc in the vac archive,
185 e05b0ff3 2008-07-03 rsc the earliest matching pattern in the file
187 e05b0ff3 2008-07-03 rsc The patterns are the same syntax accepted by the
190 e05b0ff3 2008-07-03 rsc This option may be repeated multiple times.
193 405d555f 2008-06-14 rsc lists or extracts files stored in the vac archive
194 5f1eaee2 2008-06-14 rsc .IR vacfile ,
195 405d555f 2008-06-14 rsc which can be either a vac archive string in the format
196 405d555f 2008-06-14 rsc given above or the name of a file containing one.
199 405d555f 2008-06-14 rsc arguments are given, only those files or directories
200 405d555f 2008-06-14 rsc will be extracted.
201 405d555f 2008-06-14 rsc The options are:
204 405d555f 2008-06-14 rsc Set the modification time on extracted files
205 405d555f 2008-06-14 rsc to the time listed in the archive.
208 405d555f 2008-06-14 rsc Write extracted files to standard output instead of creating a file.
211 286bb40b 2008-12-07 rsc Reduce the number of blocks read from Venti by
212 286bb40b 2008-12-07 rsc comparing the files to be stored with their counterparts
213 286bb40b 2008-12-07 rsc in the file system.
214 286bb40b 2008-12-07 rsc This option cannot be used with
218 405d555f 2008-06-14 rsc Print a list of the files to standard output rather than extracting them.
221 405d555f 2008-06-14 rsc If extracting files, print the name of each file and directory
222 405d555f 2008-06-14 rsc to standard error.
223 405d555f 2008-06-14 rsc If listing files, print metadata in addition to the names.
224 058b0118 2005-01-03 devnull .SH SOURCE
225 c3674de4 2005-01-11 devnull .B \*9/src/cmd/vac
226 058b0118 2005-01-03 devnull .SH "SEE ALSO"
227 405d555f 2008-06-14 rsc .IR vacfs (4),
228 405d555f 2008-06-14 rsc .IR venti (8)
