settings.pl: generic config file: in particular, the name of the tape
device is set here.
+settings.sh: generic config file for shell scripts. Currently only
+contains some options for the lvm snapshotter.
+
tape.*: conventionally, each tape you're going to use in the backup
cycle has a tape number, a name and a config file. The tape numbers
in use at Relativity are digit strings like `512'. The name is a
incremental backups.
<options> is a comma-separated list of <option> or <option>=<value>.
-The only currently support options are gz[i][=<compressionlevel>], to
-indicate that the whole stream should be compressed with gzip. The
-compression level defaults to 1 if gz is specified by the level isn't.
-gzi appliies only to the incrementals; gz applies to both unless gzi
-is also specified. compression level 0 means not to run gzip at all
-and is the default if gz[i] is not mentioned.
+Options supported:
+
+ gz[i][=<compressionlevel>]
+ Indicates that the whole stream should be compressed with gzip.
+ The compression level defaults to 1 if gz is specified by the
+ level isn't. gzi appliies only to the incrementals; gz applies to
+ both unless gzi is also specified. compression level 0 means not
+ to run gzip at all and is the default if gz[i] is not mentioned.
+
+ snap=<snapkind>
+ Indicates that the filesystem should be frozen before the backup
+ by using /etc/chiark-backup/snap/<snapkind>. See the head comment
+ in /etc/chiark-backup/snap/lvm for details of how this works.
expected-diffs is a config file to indicate which
filesystems should *not* be backed up. The scripts do a config