is also given.
"
+##################
+section "Commands"
+##################
+
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.
+
"
required
groupoption "prune" P
#~~~~~~~~~~~~~~~~~~~~
-"Remove a redundant snapshot"
+"Remove redundant and outdated snapshots"
group="command"
details="
- A snapshot is considered redundant if it ether belongs to
- an interval greater than the maximum number of intervals,
- or if it belongs to an interval that already contains more
- than the desired number of snapshots.
+ A snapshot is considered outdated if it belongs to an interval
+ greater than the maximum number of intervals. It is said to be
+ redundant if it belongs to an interval that already contains
+ more than the desired number of snapshots. This command gets
+ rid of such snapshots.
"
groupoption "ls" L
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.
+ 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
+ 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.
"