From 058b0118a52061ad57694c01fc8763b22b789c4d Mon Sep 17 00:00:00 2001 From: rsc Date: Mon, 3 Jan 2005 06:40:20 +0000 Subject: Some man pages. --- man/man1/vac.1 | 130 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 130 insertions(+) create mode 100644 man/man1/vac.1 (limited to 'man/man1/vac.1') diff --git a/man/man1/vac.1 b/man/man1/vac.1 new file mode 100644 index 00000000..4d3208d7 --- /dev/null +++ b/man/man1/vac.1 @@ -0,0 +1,130 @@ +.TH VAC 1 +.SH NAME +vac \- create a vac archive on Venti +.SH SYNOPSIS +.B vac +[ +.B -mqsv +] [ +.B -b +.I blocksize +] [ +.B -d +.I oldvacfile +] [ +.B -e +.I exclude +] [ +.B -f +.I vacfile +] [ +.B -i +.I name +] [ +.B -h +.I host +] +.I file ... +.SH DESCRIPTION +.I 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 +.I 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. +.PP +As an optimization, the +.B -d +and +.B -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 +.IR vac , +but simply reduce the number of write operations to Venti. +.PP +The output of +.I vac +is the hexadecimal representation of the Sha1 fingerprint of the root of the archive, in this format: +.IP +.EX +vac:64daefaecc4df4b5cb48a368b361ef56012a4f46 +.EE +.PP +Option to +.I vac +are: +.TP +.BI -b " blocksize +Specifies the block size that data will be broken into. +The units for the size can be specified by appending +.L k +to indicate kilobytes. +The default is 8k. +The size must be in the range +of 512 bytes to 52k. +.TP +.BI -d " oldvacfile +Reduce the number of blocks written to Venti by comparing the files to be stored with +the contents of an existing +.I vac +file tree given by +.IR oldvacfile . +.TP +.BI -e " exclude +Do not include the file or directory specified by +.IR exclude . +This option may be repeated multiple times. +.TP +.BI -f " vacfile +The results of +.I vac +are place in +.IR vacfile , +or the standard output if no file is given. +.TP +.BI -i " name +Include standard input as one of the input files, storing it in the archive +with the specified +.IR name . +.TP +.BI -h " host +The network address of the Venti server. +The default is taken from the environment variable +.BR venti . +.\" If this variable does not exist, then the default is the +.\" metaname +.\" .BR $venti , +.\" which can be configured via +.\" .IR ndb (6). +.TP +.B -m +Expand and merge any +.I 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 +.LR .vac . +Note, an archive is inserted by simply copying the root fingerprint and does not require +the archive to be unpacked. +.TP +.B -q +Increase the performance of the +.B -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. +.TP +.B -s +Print out various statistics on standard error. +.TP +.B -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. +.SH SOURCE +.B /usr/local/plan9/src/cmd/vac +.SH "SEE ALSO" +Plan 9's \fIvacfs\fR(4) and \fIventi\fR(8) + -- cgit v1.2.3