[email protected] (Gerhard Postpischil) writes: > I didn't say that 3390 size has any relevance, only that the same > considerations apply. Whatever physical medium is used for the FBA > disk, each platter will hold multiple records. Due to (cheap) > electronics, the gaps are of significant size, so a design with larger > blocks will get more data per track. It would be possibly to design a > drive specifically for FBA use, with better speed control, to shrink > the gaps, but at horrendous expense. Since the manufacturers profit > from selling DASD, there is limited incentive to reduce their income.
these days, all physical drives are FBA ... CKD is just hardware emulation layer on top .... for MVS, since it never got around to supporting FBA natively. As previously mentioned ... the first such was 3375 (on top of 3370 fba) ... to provide a mid-range dasd for mvs ... supporting some MVS attempt to expand into the exploding midrange market (since there was no *new* native CKD midrange disk) as periodically mentioned ... I was told that even if I gave them fully tested & integrated FBA support ... I would still have to show business case for the estimated $26m to cover document and education; roughly ten times in incremental additional sales. I wasn't allowed to use lifecycle savings as part of the business case ... and was further informed that if there there were FBA support ... customers would just switch to buying the same amount in FBA drives (no incremental, new business). misc. past posts mentioning fba, ckd, multi-track search, etc http://www.garlic.com/~lynn/submain.html#dasd misc. past posts getting to play disk engineer in bldgs. 14&15 (random trivia, during the earthquake remediation retrofit of bldg 14, enginneering was moved temporarily offsite "bldg 86") http://www.garlic.com/~lynn/subtopic.html#disk checking online sat. photos show bldgs 14&15 still standing ... but many of the ones around it are gone misc. past posts in this thread: http://www.garlic.com/~lynn/2010n.html#62 When will MVS be able to use cheap dasd http://www.garlic.com/~lynn/2010n.html#65 When will MVS be able to use cheap dasd http://www.garlic.com/~lynn/2010n.html#75 When will MVS be able to use cheap dasd http://www.garlic.com/~lynn/2010o.html#3 When will MVS be able to use cheap dasd http://www.garlic.com/~lynn/2010o.html#4 When will MVS be able to use cheap dasd http://www.garlic.com/~lynn/2010o.html#6 When will MVS be able to use cheap dasd http://www.garlic.com/~lynn/2010o.html#7 When will MVS be able to use cheap dasd -- 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: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
