This command connects to one or two backup servers and
makes an identical copy of a tape to another one. The
tape label is rewritten, so that the destination
tape keeps it's primary cartridge number, but gets
the number of the source tape as secondary number.
Thus it can be used instead of the tape with that
primary number. In fact both numbers are accepted
for backup, restore or other operations except the
copy_tape operation itself. Recursively copying an
already duplicated tape does not further change the
secondary cartridge number, so e.g. any copy of
cartridge number 3 will be usable as such. Copying
cartridge 3 to cartridge 5 and then 5 to 8 does
not make cartridge number 8 usable as cartridge 5,
but still as cartridge number 3.
When the backup server sees a cartridge with the
wrong primary number, but the correct secondary
number, this cartridge is accepted, but a warning
is written to the serverside log.
The defaults for the copying source are taken from
the client side configuration file. Default source
cartridge is the one currently loaded in the drive
on the server, that will be asked for this information.
If no target parameters are supplied, they get the
values of the appropriate source parameters as default.
So if no arguments are supplied, the current tape would
be copied to itself, what is prevented while printing
an error message.
Target (or: destination) parameters must always be
following the -D option, source parameters must be
supplied in an earlier position.
If the source tape is operated by a different server
than the target, copying goes straight from one to
the other. As two servers (with a different port
number) can reside on one host, this process does not
necessarily imply a network connection.
If source and target tape are handled by the same
server, the data to be copied must be stored somewhere
inbetween. For this purpose a temporary directory is
created on the client, where this program is started,
usually in /tmp or /var/tmp (see: tmpnam(3) ). The
filesystem, where this directory lives, must have a
free capacity of at least the largest occurring tape
file. This maximum tape file size is configured on
the server side by the parameter MaxBytesPerFile
(see: afserver.conf(8) ). If there is not enough space,
the duplication of the tape fails. The copying program
writes as many tape files to disk as it can, while
a certain amount will remain free. Then it ejects
the source cartridge and loads the target cartridge.
Now the files in the temporary directory are written
to the target tape while immediately removing files,
that are no longer needed. The more space is available
in the temporary directory, the fewer cartridge
loads/ejects are necessary.
-C <cartridge>
The number of the cartridge to use as copying
source or target (depends on argument position:
before or behind -D).
-c <configfile>
Use the given file for configuration information
-F <tape-filenumber>
If reading and writing should not start at the
beginning of the tape, but at the tape file with
the given number. This can avoid the overhead of
copying entire tapes, when only some tape files
have been appended
-h <hostname>
The name of the backup server host, where the
source or target cartridge is handled, respectively
-k <file>
Use the contents of the given file as encryption
key for authenticating to the server, where the
source or target cartridge is handled, respectively
-l <logfile>
A file to write log information to
-M <server-message-config>
The configuration to output messages from the server,
that normally are sent only via mail to a maintainer.
The first word consisting of the letters b r v and c
tells, whether to output messages during backup,
restore, verify and copy-tape, respecively. The next
words must name the service name or port number of
the single stream servers, related to the option -P .
For each multi stream service configured with -P or
in the configuration file, the respective single
stream service must be given here
-P <portnum>
The port number of the backup server on the backup
server host, where the source or target cartridge
is handled
-T <tmpdir>
use the given directory for temporarily storing the
tapefiles, when copying on one server
-v
Verbose option, tell more about what is going on
FILES
/etc/afbackup/client.conf
Client configuration file
/var/log/afbackup
The directory for logging the client backups
/var/lib/afbackup
Some internal state information of the client backups.
