Yes, the RAID devices are only there to emulate 3390 devices and that is what z/OS cares about. So the rules for 3390 devices are still valid. Try to use System Determined Blocksize, so you don't have to do the calculation anymore.
Kees. "John Compton" <john.comp...@teamwpc.co.uk> wrote in message news:<64617a3784d890478d895633c9b7037d54605f0...@ie2rd2xvs131.red002.loc al>... > (dunno where that surrounding garbage came from, but the readable test is still good) > John > > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On Behalf Of John Compton > Sent: 07 February 2012 14:33 > To: IBM-MAIN@bama.ua.edu > Subject: Physical record size query > > > ??z{S???}???? ?xj???*'???O*^??m??Z?w!j? ?????A question from one of our non-mainframe people arose t'other day: "Is 'half-track blocking' a good thing in these days of RAID arrays?" (or words to that effect). > > And I don't know enough about RAID architecture to answer. > > I first learnt about half-track blocking when I was a SysProg on DOS/VSE/AF systems & when I had to deal with LIOCS and PIOCS. Since then, I guess I've sort of become 'married' to it (and, at the risk of getting badly flamed, I'd venture to say that most of us here use the technique 'by default', rather than putting any deep thought into the matter.) > > Whenever I can exert any control over a file allocation, I do my best to ensure that the physical record size is as close as possible to 27998 bytes. > > > So the question stands... > In situations where a RAID array is used for disk storage (as opposed to discrete devices, headed up by a controller), is half-track blocking: > (a) worth bothering about; and (b) if it's worth bothering about, is 27998 bytes the best number? > B?KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK CB????P?KSPRS? ?X????X?H > ? ?Y????? > ?\??]?HX??\??[?? ?X?[???B??[?[XZ[ ?\? ?\???[XK?XK?Y H ?] HY\??Y?N?S???P?KSPRS?B > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN ******************************************************** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. Koninklijke Luchtvaart Maatschappij N.V. (also known as KLM Royal Dutch Airlines) is registered in Amstelveen, The Netherlands, with registered number 33014286 ******************************************************** ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN
