From 78e51a8c6678b6e3dff3d619aa786669f531f4bc Mon Sep 17 00:00:00 2001 From: rsc Date: Fri, 14 Jan 2005 03:45:44 +0000 Subject: checkpoint --- man/man1/vac.html | 160 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 160 insertions(+) create mode 100644 man/man1/vac.html (limited to 'man/man1/vac.html') diff --git a/man/man1/vac.html b/man/man1/vac.html new file mode 100644 index 00000000..71f121ff --- /dev/null +++ b/man/man1/vac.html @@ -0,0 +1,160 @@ + +vac(1) - Plan 9 from User Space + + + + +
+
+
VAC(1)VAC(1) +
+
+

NAME
+ +
+ + vac – create a vac archive on Venti
+ +
+

SYNOPSIS
+ +
+ + vac [ −mqsv ] [ −b blocksize ] [ −d oldvacfile ] [ −e exclude + ] [ −f vacfile ] [ −i name ] [ −h host ] file ...
+ +
+

DESCRIPTION
+ +
+ + Vac creates an archival copy of Plan 9 file trees on Venti. It + can be used to build a simple backup system. One of the unusual + properties of Venti is that duplicate blocks are detected and + coalesced. When vac is used on a file tree that shares data with + an existing archive, the consumption of storage will be approximately + equal to an incremental backup. This reduction in storage consumption + occurs transparently to the user. +
+ + As an optimization, the −d and −q options, described below, can + be used to explicitly create an archive relative to an existing + archive. These options do not change the resulting archive generated + by vac, but simply reduce the number of write operations to Venti. + +
+ + The output of vac is the hexadecimal representation of the Sha1 + fingerprint of the root of the archive, in this format:
+ +
+ + vac:64daefaecc4df4b5cb48a368b361ef56012a4f46
+ +
+ + +
+ Option to vac are:
+ −b blocksize
+ +
+ + Specifies the block size that data will be broken into. The units + for the size can be specified by appending k to indicate kilobytes. + The default is 8k. The size must be in the range of 512 bytes + to 52k.
+ +
+ −d oldvacfile
+ +
+ + Reduce the number of blocks written to Venti by comparing the + files to be stored with the contents of an existing vac file tree + given by oldvacfile.
+ +
+ −e exclude
+ +
+ + Do not include the file or directory specified by exclude. This + option may be repeated multiple times.
+ +
+ −f vacfile
+ +
+ + The results of vac are place in vacfile, or the standard output + if no file is given.
+ +
+ −i name
+ +
+ + Include standard input as one of the input files, storing it in + the archive with the specified name.
+ +
+ −h host
+ +
+ + The network address of the Venti server. The default is taken + from the environment variable venti.
+ +
+ −m    Expand and merge any vac archives that are found while reading + the input files. This option is useful for building an archive + from a collection of existing archives. Each archive is inserted + into the new archive as if it had been unpacked in the directory + in which it was found. Multiple archives can be unpacked in + +
+ + a single directory and the contents will be merged. To be detected, + the archives must end in .vac. Note, an archive is inserted by + simply copying the root fingerprint and does not require the archive + to be unpacked.
+ +
+ −q    Increase the performance of the −d option by detecting unchanged + files based on a match of the files name and other meta data, + rather than examining the contents of the files.
+ −s    Print out various statistics on standard error.
+ −v    Produce more verbose output on standard error, including the + name of the files added to the archive and the vac archives that + are expanded and merged.
+ +
+

SOURCE
+ +
+ + /usr/local/plan9/src/cmd/vac
+ +
+

SEE ALSO
+ +
+ + Plan 9’s vacfs(4) and venti(8)
+ +
+ +

 +
+
+ + +
+
+
+Space Glenda +
+
+ + -- cgit v1.2.3