Using CA Tape Encryption in Your z/OS Environment › Integrated Compression for Symmetric Key Encryption › SMF Recording of Compression Overhead

SMF Recording of Compression Overhead

The specific overhead associated with compression and expansion activity is recorded in the CA Tape Encryption SMF subtype 32 record. The subtype 32 record contains the following information:

• The number of bytes processed prior to compression.
• The number of bytes processed after compression.
• The overall rate of compression.
• The minimum compress rate in effect during processing.
• The CPU time consumed by compression.

For more information about Systems Management Facility record tracking, see the Configuration Guide.

The CPU time fields BSMF32CPUIN, for reading a tape, and BSMF32CPUOU, for writing to a tape, indicate the total CPU times. This includes the encryption or decryption CPU time as well as the compression or expansion CPU time. These times are also reported separately in the BSMF32CPUCM field. Therefore, when you use compression you can calculate the overhead associated with encryption or decryption by subtracting the compression time (BSMF32CPUCM) from the total CPU time (BSMF32CPUIN or BSMF32CPUOU).