X-Git-Url: http://git.tuebingen.mpg.de/?p=dss.git;a=blobdiff_plain;f=dss.ggo;h=6ac2a39d12b9eb24bd36865a7554a24b252f94af;hp=9587dd24c7b11a439b2c63335ba922361e1cf988;hb=d13861de884e6d76fb854d1869e7c4373d619b6e;hpb=15eb99dcf9a30f8c8d488d5bc3c92130cf828d60

diff --git a/dss.ggo b/dss.ggo
index 9587dd2..6ac2a39 100644
--- a/dss.ggo
+++ b/dss.ggo
@@ -3,7 +3,7 @@
 # Licensed under the GPL v2. For licencing details see COPYING.
 
 package "dss"
-version "0.1.5"
+version "0.1.6"
 purpose "the dyadic snapshot scheduler
 
 dss creates hardlink-based snapshots of a given directory on a remote
@@ -38,14 +38,12 @@ option "daemon" d
 #~~~~~~~~~~~~~~~~
 "Run as background daemon"
 flag off
-dependon="logfile"
 details="
-	Note that dss refuses to start in daemon mode if no logfile
-	was specified. This option is mostly useful in conjuction
-	with the -R option described below.
+	This option is mostly useful in conjunction with the -R option
+	described below.
 
-	Note that it is not possible to change whether dss runs as
-	background daemon by sending SIGHUP.
+	Note that it is not possible to change whether dss runs as background
+	daemon by sending SIGHUP.
 "
 
 option "dry-run" D
@@ -77,10 +75,14 @@ option "logfile" -
 "Logfile for the dss daemon process"
 string typestr="filename"
 optional
+default="/dev/null"
 details = "
 	This option is only honored if both --run and --daemon are
-	given. Otherwise it is silently ignored and log output is
-	written to stderr.
+	given. Otherwise it is silently ignored and log output is written
+	to stderr.
+
+	The default value means that nothing will be logged in daemon mode
+	unless this option is given.
 "
 
 ##################
@@ -244,6 +246,26 @@ details="
 		--rsync-option --exclude --rsync-option /proc
 "
 
+option "max-rsync-errors" -
+"Terminate after this many rsync failures"
+int typestr="count"
+default="10"
+optional
+details="
+	Only relevant when operating in --run mode (see above). If
+	the rsync process exits with a fatal error, dss restarts
+	the command in the hope that the problem is transient
+	and subsequent rsync runs succeed. After the given number
+	of consecutive rsync error exits, however, dss gives up,
+	executes the exit hook and terminates. Set this to zero if
+	dss should exit immediately on the first rsync error.
+
+	The only non-fatal error is when rsync exits with code 24. This
+	indicates a partial transfer due to vanished source files
+	and happens frequently when snapshotting a directory which
+	is concurrently being modified.
+"
+
 ###################
 section "Intervals"
 ###################
@@ -255,22 +277,21 @@ int typestr="days"
 default="4"
 optional
 details="
-	dss snapshot aging is implemented in terms of intervals. There
-	are two command line options related to intervals: the
-	duration u of a \"unit\" interval and the number n of those
-	unit intervals.
-
-	dss removes any snapshots older than n times u and tries to
-	keep 2^(n - k - 1) snapshots in interval k, where the interval
-	number k counts from zero, zero being the most recent unit
-	interval.
-
-	In other words, the oldest snapshot will at most be u * n days
-	(= 20 days if default values are used) old.  Moreover, there
-	are at most 2^n - 1 snapshots in total (i. e. 31 by default).
-	Observe that you have to create at least 2^(n - 1) snapshots
-	each interval for this to work out because that is the number
-	of snapshots in interval zero.
+	Snapshot aging is implemented in terms of intervals. There are two
+	command line options related to intervals: the duration u of a unit
+	interval and the number of unit intervals, denoted n below.
+
+	dss removes snapshots older than n times u and tries to keep 2^(n -
+	k - 1) snapshots in interval k, where the interval number k counts
+	from zero to n - 1, with zero being the most recent unit interval.
+
+	Hence the oldest snapshot will at most be u * n days old (4 days *
+	5 intervals = 20 days, if default values are used). Moreover, there
+	are at most 2^n - 1 snapshots in total (2^5 - 1 = 31 by default). Note
+	that for this to work out your system must be fast enough to create at
+	least 2^(n - 1) snapshots per unit interval (16 snapshots in 4 days =
+	one snapshot in 6 hours), because this is the number of snapshots in
+	interval zero.
 "
 
 option "num-intervals" n
@@ -279,6 +300,10 @@ option "num-intervals" n
 int typestr="num"
 default="5"
 optional
+details="
+	Note that increasing this number by one doubles the total number of
+	snapshots. See the documentation of --unit-interval above.
+"
 
 ###############
 section "Hooks"
@@ -431,13 +456,10 @@ option "keep-redundant" k
 "Prune by disk space only"
 flag off
 details="
-	If this flag is not given dss removes redundant and outdated
-	snapshots automatically.
-
-	Otherwise, this feature is deactivated so that snapshots are
-	only being removed in case disk space or number of free inodes
-	becomes low. Use this flag if the file system containing the
-	destination directory is used for snapshots only.
+	By default, redundant and outdated snapshots are removed automatically
+	to keep the number of snapshots in harmony with the configured
+	policy. If this flag is given, dss removes such snapshots only if
+	disk space or number of free inodes becomes low.
 "
 
 option "min-complete" -