remember no real CKD devices have been made for decades ... all being simulated on industry standard fixed-block ... need a fair amount electronics and processing between the emulated CKD layer and the real fixed-block hardware (whether fixed-block spinning disks or fixed-block SSD).
a lot of the CKD optimization work ... may actually have little or no meaning by the time things reach the fixed-block physical device. [email protected] (Matt Hogstrom) writes: > Out of curiosity, its been a while since I did storage admin but it > occurred to me that for the most part a lot of the work in defragging, > worrying about disk geometry and other issues are really not / less of > an issue with cache and SSD technologies. So, perhaps naive on my > part, but it would seem to me the work to “defrag” is really more to > keep up the legacy z/OS concepts like # of extents, CKD processing for > PDS’, etc. Are there benefits to defragging these days apart from the > consequences of the limitations from older architectures and paradigms > like directory blocks and member placement? -- virtualization experience starting Jan1968, online at home since Mar1970 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
