copy_tape - make a duplicate of a tape

copy_tape [ -v ] [ -c <configuration-file> ] [ -l <logfile> ] [ -T <tmpdir> ] [ -M <server-message-config> ] [ -h <source-server> ] [ -P <source-serverport> ] [ -F <tape-filenumber> ] [ -C <source-cartridge> ] [ -k <source-encryption-key-file> ] [ -D [ -h <target-server> ] [ -P <target-serverport> ] [ -C <target-cartridge> ] [ -k <target-encryption-key-file> ] ]

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

/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.

afclientconfig(8), xafclientconfig(8), full_backup(8), incr_backup(8), afverify(8), afrestore(8), xafrestore(8), update_indexes(8), copy_tape(8), afclient.conf(8), afserver(8), afmserver(8), afserver.conf(8), tar(1)

afbackup was written by Albert Fluegel (af@muc.de).