\h'-\w'\fB\\$1\ \fP'u'\fB\\$1\ \fP\c
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.TH rsync-backup 8 "7 October 2012" rsync-backup
+.SH NAME
+rsync-backup \- back up files using rsync
.SH SYNOPSIS
.B rsync-backup
-.RB [ \-v ]
+.RB [ \-nv ]
.RB [ \-c
.IR config-file ]
.SH DESCRIPTION
.B \-V
output).
.TP
+.B \-n
+Don't actually take a backup, or write proper logs: instead, write a
+description of what would be done to standard error.
+.TP
.B \-v
Produce verbose progress information on standard output while the backup
is running. This keeps one amused while running a backup
in this case.
This command clears the
.B like
-list.
+list, and resets the retention policy to its default (i.e., the to
+policy defined prior to the first
+.B host
+command).
.TP
.BI "like " "host\fR ..."
Declare that subsequent filesystems are `similar' to like-named
Expiry considers each existing dump against the policy lines in order:
the last applicable line determines the dump's fate \(en so you should
probably write the lines in decreasing order of duration.
+.PP
+Groups of
+.B retain
+commands between
+.B host
+and/or
+.B backup
+commands collectively define a retention policy. Once a policy is
+defined, subsequent
+.B backup
+operations use the policy. The first
+.B retain
+command after a
+.B host
+or
+.B backup
+command clears the policy and starts defining a new one. The policy
+defined before the first
+.B host
+is the
+.I default
+policy: at the start of each
+.B host
+stanza, the policy is reset to the default.
+.TP
+.BI "retry " count
+The
+.B live
+snapshot type (see below) doesn't prevent a filesystem from being
+modified while it's being backed up. If this happens, the
+.B fshash
+pass will detect the difference and fail. If the filesystem in question
+is relatively quiescent, then maybe retrying the backup will result in a
+successful consistent copy. Following this command, a backup which
+results in an
+.B fshash
+mismatch will be retried up to
+.I count
+times before being declared a failure.
.TP
.BI "snap " type " " \fR[\fIargs\fR...]
Use the snapshot
.I type
for subsequent backups. Some snapshot types require additional
-arguments, which may be supplied here.
+arguments, which may be supplied here. This command clears the
+.B retry
+counter.
.SS Configuration variables
The following shell variables may be overridden by the configuration
file.
.TP
+.B HASH
+The hash function to use for verifying archive integrity. This is
+passed to the
+.B \-H
+option of
+.BR fshash ,
+so it must name one of the hash functions supported by your Python's
+.B hashlib
+module.
+The default is
+.BR sha256 .
+.TP
.B MAXLOG
The number of log files to be kept for each filesystem. Old logfiles
are deleted to keep the total number below this bound. The default
.I mntbkpdir
is the backup mount directory configured at build time.
.TP
-.B HASH
-The hash function to use for verifying archive integrity. This is
-passed to the
-.B \-H
-option of
-.BR fshash ,
-so it must name one of the hash functions supported by your Python's
-.B hashlib
-module. The default is
-.BR sha256 .
.SS Hook functions
The configuration file may define shell functions to perform custom
actions at various points in the backup process.
At the top level is one directory for each client host. There are also
some special entries:
.TP
+.B \&.rsync-backup-store
+This file must be present in order to indicate that a backup volume is
+present (and not just an empty mount point).
+.TP
.B fshash.cache
The cache database used for improving performance of local file
hashing. There may be other