offsite - prepares recent backups to be taken offsite
offsite [options]
Options: --config <f> read configuration from <f> --nosyslog log to stdout instead of syslog --facility <f> log to syslog facility <f> --backupdir <d> find backups in directory <d> --workdir <d> create ISO images in directory <d> --blocksize <b> write in multiples of <b> bytes --maxfilesize <b> split files larger than <b> bytes --maximagesize <b> don't put more than <b> bytes into one image --pwfile <f> encrypt with passphrase from file <f> --dryrun don't create any files --help print a usage summary --man read the full man page
The offsite program prepares backup files created by the backup program to be transferred to removable media to be taken offsite. This includes splitting large files, splitting files across media size boundaries, and encrypting the split files using GPG. The files selected to be taken offsite are the most recent level zero backup of each filesystem, along with the most recent level one backup if one is present.
The program will create one directory beneath the work directory for each
set of files to be put onto one media. Within this directory, files will be
split if they exceed a configurable maximum size, of if they will not fit
on one media. The --dryrun option is useful to see which files would be
split and how much media you will need.
To secure the backup data being taken offsite, the files are encrypted with GPG using conventional (symmetric) encryption. This mode requires no keys or keyring for encryption or decryption; only a passphrase is used. Files are split if necessary before being encrypted, so to restore from offsite media you must decrypt all the files before reassembling them.
Originally this program was intended to produce images for DVD media, but the image size and file size can be adjusted for CD media or any other media. It is assumed that the output files will be made into ISO-9660 images, but this program does not attempt to create the images.
Almost all options can be specified both on the command line and in the configuration file. When an option is specified in both places, the value supplied on the command line is used. The configuration file is described in the CONFIGURATION FILE section.
Read configuration from file f. If not specified, configuration is read from /etc/backup/backup.conf. The configuration file is described in the CONFIGURATION FILE section.
Log to stdout instead of syslog. This is the default.
When using syslog, log to facility f. The default is user.
The corresponding configuration file option is SyslogFacility.
Look for backups in directory d. Files ending in .bz2 are assumed to be
backups. There is no default; this option must be specified.
The corresponding configuration file option is BackupDirectory.
Create subdirectories containing output files beneath directory d. This may be within the backup directory. There is no default; this option must be specified.
The corresponding configuration file option is WorkDirectory.
When splitting and compressing files, work in multiples of b bytes. The
larger this number, the more efficient dd is. If the backups span
multiple discs, somewhere between 0 and b bytes will be wasted at the
end of all but the last disc. The default is 4096.
The corresponding configuration file option is BlockSize.
Force a file to be split if it is larger than b bytes. This is useful
to work around the inability of mkisofs to add files larger than 2GB
to an ISO-9660 image. The default is 2000000000, which is slightly less
than 2GB.
The corresponding configuration file option is MaxFileSize.
Put no more than b bytes in one image. If b is not a multiple of the block size, then less than b bytes will be in each full image. The default is 4698112000, which is 99.9% of the capacity of a DVD.
The corresponding configuration file option is MaxImageSize.
Read the passphrase used for GPG encryption from file f. GPG is used for conventional (symmetric) encryption using no keys, only a passphrase. The first line is read from f, any newline is removed, and the result is used as the passphrase. There is no default; this option must be specified.
The corresponding configuration file option is PasswordFile.
Don't encrypt or create any files; just show what would be done. This is useful to get an idea of how many images would be created and which files would be split.
Print a usage summary and exit.
Read the full man page for this program.
Options are specified in the configuration in lines that look like:
option=value
You may add any amount of whitespace on either side of the =, so the
following will also work:
option = value