From 6bb663afeea85733b2037ce8a027efa0a15c5aad Mon Sep 17 00:00:00 2001 From: Andre Noll Date: Fri, 21 Mar 2008 23:59:20 +0100 Subject: [PATCH] dss.ggo: Minor documentation improvements. --- dss.ggo | 56 +++++++++++++++++++++++++------------------------------- 1 file changed, 25 insertions(+), 31 deletions(-) diff --git a/dss.ggo b/dss.ggo index 171142e..6e222d2 100644 --- a/dss.ggo +++ b/dss.ggo @@ -29,9 +29,6 @@ details=" file override any options that were previously given at the command line. This allows to change the configuration of a running dss process on the fly by sending SIGHUP. - - Note that it is not possible to change whether dss runs as - background daemon by sending SIGHUP. " option "daemon" d @@ -43,6 +40,9 @@ 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. + + Note that it is not possible to change whether dss runs as + background daemon by sending SIGHUP. " option "dry-run" D @@ -66,7 +66,7 @@ int typestr="level" default="3" optional details=" - Lower values mean less verbose logging. + Lower values mean more verbose logging. " option "logfile" - @@ -82,8 +82,9 @@ details=" defgroup "command" #================= groupdesc=" - dss supports a couple of commands each of which corresponds to a different - command line option. Exactly one of these options must be given. + dss supports a couple of commands each of which corresponds + to a different command line option. Exactly one of these + options must be given. " required @@ -92,9 +93,10 @@ groupoption "create" C "Create a new snapshot" group="command" details=" - Execute the rsync command to create a new snapshot. Note that this - command does not care about free disk space. + Execute the rsync command to create a new snapshot. Note that + this command does not care about free disk space. " + groupoption "prune" P #~~~~~~~~~~~~~~~~~~~~ "Remove a redundant snapshot" @@ -203,29 +205,21 @@ 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 of a - \"unit\" interval and the number of those unit intervals. - - dss removes any snapshots older than the given number of intervals - times the duration of a unit interval and tries to keep the following - number of snapshots per interval: - - interval number number of snapshots - =============================================== - 0 2 ^ (num-intervals - 1) - 1 2 ^ (num-intervals - 2) - 2 2 ^ (num-intervals - 3) - ... - num-intervals - 2 2 - num-intervals - 1 1 - num-intervals 0 - - In other words, the oldest snapshot will at most be unit_interval * - num_intervals old (= 5 days * 4 = 20 days if default values are used). - Moreover, there are at most 2^num_intervals - 1 snapshots in total - (i. e. 31 by default). Observe that you have to create at least - 2 ^ (num_intervals - 1) snapshots each interval for this to work out. + 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^(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. " option "num-intervals" n -- 2.39.5