SAP Note 13372 - BRBACKUP reaches end of tape

Symptom:

When you back up to tape using the BRBACKUP tool, the end of the
tape is reached, and cpio reports the following under UNIX:
BR278E Command ... cpio ... :
"End of tape.", "End of media", "End of volume" (according to platform)
or "Cannot prompt for more media" ...
Under NT the following message is issued:
cpio: write error on file "...": The physical end of the tape has
been reached.
BR279E Return code from ... cpio ...
BR222E Copying ... failed.
BRBACKUP terminates with errors.

Reason and Prerequisites

There are several different possible causes:
1. tape_size specified too large in init.sap

2. The compression rates used internally by BRBACKUP during hardware
compression are no longer up-to-date. BRBACKUP therefore tries to
save too many files on one tape. This situation occurs if the dummy
compression (compress = only) was executed a long time ago or
directly after a database reorganization, after a larger data copy
or after a release upgrade.

3. AIX only: When SMIT parameter tape block size is set to 512
(in the SMIT submenu units/devices), the block size of 5 KB,
which is normally used by cpio, is overwritten, and the tape cannot
reach its full capacity due to the gaps that are created.

4. init.sap parameter "compress" is set incorrectly
(not appropriate for the compression type used - hardware/software
- or no compression).

Solution
1.: Correct parameter tape_size in init.sap
(see Note 8707)
If you use hardware compression: many manufacturers specify the
tape capacity in the amount of uncompressed data (e.g. 6 GB).
However, the BRBACKUP profile must contain the actual tape size,
e.g. the quantity of compressed data (e.g. 1600MB).
2.: If hardware-compressed tape stations are used, SAP recommends that
you make a dummy compression of the database using parameter
"compress = only" at least once a month. In this way you can find
out the current compression rates of the database files. If you use
these parameters, no backup will be started. After larger changes
to the database (reorganization, release upgrade, copying larger
amounts of data), you should always start dummy compression.
Under Unix: Use option "-b 12" in the definition of the
compress command here (init.sap-parameter compress_cmd):
compress_cmd = "compress -b 12 -c $ > $"
Under Windows: Use option "-l 0" in the definition of the
compress command here (init.sap-parameter compress_cmd):
compress_cmd = "mkszip -l 0 -c $ > $"
The compress rates thus determined better correspond to the actual
hardware compression rates and thus permit an optimal distribution
of the files and optimal use of the data media.
3.: Set parameter tape-blocksize in SMIT to 0 (= variable)..
4.: Correct parameter compress in init.sap
( [yes | no | hardware] ; see documentation)

Key word: BRBACKUP