cback-amazons3-sync [switches] sourceDir s3BucketUrl


This is the Cedar Backup Amazon S3 sync tool. It synchronizes a local directory to an Amazon S3 cloud storage bucket. After the sync is complete, a validation step is taken. An error is reported if the contents of the bucket do not match the source directory, or if the indicated size for any file differs.

Generally, one can run the cback-amazons3-sync command with no special switches. This will start it using the default Cedar Backup log file, etc. You only need to use the switches if you need to change the default behavior.



The source directory on a local disk.


The URL specifying the location of the Amazon S3 cloud storage bucket to synchronize with, like s3://


-h, --help

Display usage/help listing.

-V, --version

Display version information.

-b, --verbose

Print verbose output to the screen as well writing to the logfile. When this option is enabled, most information that would normally be written to the logfile will also be written to the screen.

-l, --logfile

Specify the path to an alternate logfile. The default logfile file is /var/log/cback.log.

-o, --owner

Specify the ownership of the logfile, in the form user:group. The default ownership is root:adm, to match the Debian standard for most logfiles. This value will only be used when creating a new logfile. If the logfile already exists when the cback script is executed, it will retain its existing ownership and mode. Only user and group names may be used, not numeric uid and gid values.

-m, --mode

Specify the permissions for the logfile, using the numeric mode as in chmod(1). The default mode is 640 (-rw-r-----). This value will only be used when creating a new logfile. If the logfile already exists when the cback script is executed, it will retain its existing ownership and mode.

-O, --output

Record some sub-command output to the logfile. When this option is enabled, all output from system commands will be logged. This might be useful for debugging or just for reference.

-d, --debug

Write debugging information to the logfile. This option produces a high volume of output, and would generally only be needed when debugging a problem. This option implies the --output option, as well.

-s, --stack

Dump a Python stack trace instead of swallowing exceptions. This forces Cedar Backup to dump the entire Python stack trace associated with an error, rather than just progating last message it received back up to the user interface. Under some circumstances, this is useful information to include along with a bug report.

-D, --diagnostics

Display runtime diagnostic information and then exit. This diagnostic information is often useful when filing a bug report.


This command returns 0 (zero) upon normal completion, and several other error codes related to particular errors.


The Python interpreter version is < 2.5.


Error processing command-line arguments.


Error configuring logging.


Backup was interrupted with a CTRL-C or similar.


Other error during processing.


This tool is a wrapper over the Amazon AWS CLI interface found in the aws(1) command. Specifically, cback-amazons3-sync invokes "aws s3 sync" followed by "aws s3api list-objects".

Cedar Backup itself is designed to run as root. However, this command can be run safely as any user that is configured to use the Amazon AWS CLI interface. The aws(1) command will be executed by the same user which is executing cback-amazons3-sync.

You must configure the AWS CLI interface to have a valid connection to Amazon S3 infrastructure before using cback-amazons3-sync. For more information about how to accomplish this, see the Cedar Backup user guide.

RELATED TO cback-amazons3-sync…


/var/log/cback.log - Default log file


Report bugs to <[email protected]>.


Written by Kenneth J. Pronovici <[email protected]>.


Copyright (c) 2014 Kenneth J. Pronovici.

This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.