Using CA Tape Encryption in Your z/OS Environment › Integrated Compression for Symmetric Key Encryption › Using FDR or DFDSS with ExHPDM

Using FDR or DFDSS with ExHPDM

ExHPDM is designed to speed up the backup process by interleaving the output stream of many concurrent backup jobs such as FDR and DFDSS to a smaller number of tape devices. Use of the tape drives and media is optimized because data is sent to the drive at channel speed and fewer tape cartridges are needed for the output. Data is transferred from the backup jobs to the ExHPDM address space through disk files optimized for fast access. In this scenario, when CA Tape Encryption is configured to encrypt and compress the tapes written by ExHPDM, it is forced to "single thread" a process that normally would be done concurrently by the individual FDR or DFDSS backup jobs. Naturally, this will elongate the time it takes to complete writing the data.

In this situation CA recommends that compression be turned on in your FDR and DFDSS backup jobs rather than having CA Tape Encryption attempt to compress the ExHPDM output tapes prior to encryption. This approach reduces the amount of data sent to ExHPDM and makes better use of system resources by increasing the amount of concurrent processing.

Note: Activating compression in your backup job may change storage requirements and may reduce the number of volumes that each backup job may process. You should review your FDR and DFDSS product documentation for details on how to activate compression and any related storage requirements.