Edit initsid.sap (initIDS.sap)

The file /oracle/IDS/dbs/initIDS.sap contains the SAP backup profile. Here the size of the tape to be used, type of compression and so on need to be defined. To get this running with sapdba / brbackup, we changed the following values:

compress = hardware
archive_function = copy_delete_save
cpio_flags = "-ov --format=newc --block-size=128 --quiet"
cpio_in_flags = "-iuv --block-size=128 --quiet"
tape_size = 38000M
tape_address = /dev/nsa0
tape_address_rew = /dev/sa0

Explanations:

compress: The tape we use is a HP DLT1 which does hardware compression.

archive_function: This defines the default behavior for saving Oracle archive logs: new logfiles are saved to tape, already saved logfiles are saved again and are then deleted. This prevents lots of trouble if you need to recover the database, and one of the archive-tapes has gone bad.

cpio_flags: Default is to use -B which sets block size to 5120 Bytes. For DLT Tapes, HP recommends at least 32 K block size, so we used --block-size=128 for 64 K. --format=newc is needed because we have inode numbers greater than 65535. The last option --quiet is needed as otherwise brbackup complains as soon as cpio outputs the numbers of blocks saved.

cpio_in_flags: Flags needed for loading data back from tape. Format is recognized automatically.

tape_size: This usually gives the raw storage capability of the tape. For security reason (we use hardware compression), the value is slightly lower than the actual value.

tape_address: The non-rewindable device to be used with cpio.

tape_address_rew: The rewindable device to be used with cpio.