SAP Note 13994 - Long runtimes when saving with BRBACKUP

Symptom:

Runtimes are much longer than normal when you save.

Reason and Prerequisites

Cause 1.
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There is a high CPU load, possibly due to looping processes. This has a negative effect in particular if you use software compression (compress = yes in init.sap)

Cause 2.
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The dd ouput on tape is not blocked when you save to a remote host.
AIX only: The SMIT setting for "tape block size" is not equal to 0.
The "cpio_flags" do not define a block for the cpio output.

Cause 3.
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The cpio performance is poor on Windows NT.

Solution

Solution 1.
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Check the CPU load: using process lists (command ps), for example. Identify processes that have used more than 1,000 CPU seconds. If these are looping processes (for example, the CPU load grows quickly), kill them or boot the host.

Solution 2.
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Include the option bs=5k in init.sap parameter copy_in_cmd and copy_out_cmd:
copy_in_cmd = "dd bs=64k if=$"
copy_out_cmd = "dd bs=64k of=$"
You can also use block sizes other than 64k.
AIX only: Set the SMIT setting for "tape block size" to 0 (variable block size).
The init.sap parameter cpio_flags should define a block for the cpio output, for example, cpio_flags = -ovB. "B" means that blocks of 5120 bytes are written to tape.
If this burdens the operating system, you can work with larger blocking factors and therefore achieve shorter save times.

Solution 3.
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As of BRBACKUP 3.1, you can use the dd command for backups of the database files along with the cpio. This can improve the performance. For more information, see Note 71058.
If this does not solve the problem, your only solution is to change the backup method:

3.1. Using the SAP backup library with RMAN. To do this, change the following inittape_copy_cmd = rman
and activate the SAP backup library (Note 142635).

3.2. Use an external backup tool through the BACKINT interface:
backup_dev_type = util_file | util_file_online
You can find information about partners who support this interface in Note 83792.

Keyword: BRBACKUP