This discussion is all about use cases and data types. As mentioned in this thread, not all data supports zEDC and it's highly unlikely that everything will be encrypted. I would recommend analyzing the data written to your tape environment and determine if it would be beneficial to turn off tape compression for a specific workload. (Via data class).
DSS was one use case that was mentioned. I would never use the COMPRESS option of DSS if you have the zEDC feature. If you are targeting disk, then use ZCOMPRESS (zEDC). If you are targeting tape, then it's a trade-off with using zEDC and TS7700 compression. zEDC will use host cpu. DSS has the smarts not to try to compress a data set that is already compressed and or encrypted. If cpu consumption is a concern, then just use TS7700 compression and no DSS compression. This is especially true for full volume dump to tape. HSM is a use case for which zEDC is a best practice. It will improve throughput and slightly reduce CPU. We recommend that you use ZCOMPRESS for both migration and backup. (If you use HSM Dump, then it's the same recommendation as DSS. Just use TS7700 compression to not experience a cpu increase). For your HSM migration/backup data classes, disable TS7700 compression. For Recycle, assign a data class that utilizes TS7700 compression because you need it to continue to compress old data that wasn't migrated/backed up with zEDC. For other tape data, determine if the application is already compressing and or encrypting the data and enable/disable TS7700 compression as appropriate. Glenn Wilcock, DFSMS Chief Product Owner ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
