However, there is one exception to this rule: The run subcommand
re-reads the configuration file when it receives the HUP signal. In
this case the options in the config file override any options that
- were previously given at the command line. This allows to change the
+ were previously given at the command line. This allows changing the
configuration of a running dss process by sending SIGHUP.
[/help]
[option loglevel]
This option is mandatory for all subcommands except kill.
[/help]
+ [option mountpoint]
+ summary = abort if destination directory is not a mountpoint
+ [help]
+ This option checks whether a file system is mounted on the directory
+ specified as the argument to --dest-dir. Operation proceeds only
+ if this is the case. Otherwise dss exits unsuccessfully without
+ performing any action. Use this option to prevent snapshot creation
+ if the snapshot file system is not mounted.
+
+ This option is silently ignored for subcommands which do not depend
+ on the destination directory.
+ [/help]
[option Rsync-options]
summary = Controlling how rsync is run
flag ignored
Set this if the user that runs dss is different from the user on the
remote host.
[/help]
+ [option checksum]
+ summary = run rsync with --checksum occasionally
+ typestr = permille
+ arg_info = required_arg
+ arg_type = uint32
+ default_val = 0
+ [help]
+ If a file on the backup becomes corrupt in a way that file size
+ and modification time still match the original file, rsync will not
+ consider the file for transfer ("quick check"). Hence the corruption
+ stays on the backup until the file is modified on the source.
+ The --checksum option of rsync disables the quick check and compares
+ the contents of each file, fixing such corruptions. Since computing
+ the checksums adds a significant slowdown due to a lot of disk I/O,
+ the option is not enabled by default.
+
+ The argument to the --checksum option of dss is a number between 0
+ and 1000, inclusively, which determines the probability of adding
+ --checksum to the rsync options each time a snapshot is created. The
+ default value zero means to never add the option. The value 100 will
+ create every tenth snapshot (on average) using checksums, and the
+ value 1000 will always pass --checksum to rsync.
+ [/help]
[option rsync-option]
short_opt = O
summary = further rsync options
typestr = percent
default_val = 2
[help]
- This is like --min-free-mb but allows to specify the amount of
- free disk space as a percentage. It is not recommended to set both
+ This is like --min-free-mb but the amount of free disk space
+ is specified as a percentage. It is not recommended to set both
--min-free-mb and --min-free-percent to zero as this will cause your
file system to fill up quickly.
[/help]
Sending SIGHUP causes the running dss process to reload its config file.
[/help]
+ [option wait]
+ short_opt = w
+ summary = wait until the signalled process has terminated
+ [help]
+ This option is handy for system shutdown scripts which would like
+ to terminate the dss daemon process.
+
+ Without --wait the dss process which executes the kill subcommand
+ exits right after the kill(2) system call returns. At this point the
+ signalled process might still be alive (even if SIGKILL was sent).
+ If --wait is given, the process waits until the signalled process
+ has terminated or the timeout expires.
+
+ If --wait is not given, the kill subcommand exits successfully if
+ and only if the signal was sent (i.e., if there exists another dss
+ process to receive the signal). With --wait it exits successfully
+ if, additionally, the signalled process has terminated before the
+ timeout expires.
+
+ It makes only sense to use the option for signals which terminate dss.
+ [/help]
+[subcommand configtest]
+ purpose = run a configuration file syntax test
+ [description]
+ This command checks the command line options and the configuration
+ file for syntactic correctness. It either reports "Syntax Ok" and
+ exits successfully or prints information about the first syntax error
+ detected and terminates with exit code 1.
+ [/description]
[section copyright]
Written by Andre Noll
projects / dss.git / blobdiff