stevej@synopsys.synopsys.com (Steven Jukoff) (05/30/90)
In SCO UNIX v3.2 I do an "sfmt" on my ESDI disk and eventually it asks me for skew as in: Boot : sfmt . . . skew [0-15]? 1 . . . I don't know if this is disk skew or head skew or cylinder skew, etc. What does skew mean and what is the correct answer? Hardware: SMS OMTI 8620 controller board attached to a Micropolis 1355. Both SCO and MICROPOLIS claim they do not use skew, so what's the answer? And what is the penalty for being wrong? Steven Jukoff, Phone: (415)962-5407 Synopsys, Inc. FAX: (415)965-8637 1098 Alta Ave DDN: stevej@synopsys.com Mountain View, CA 94043 UUCP: ..!uunet!fernwood!synopsys!stevej
davidsen@sixhub.UUCP (Wm E. Davidsen Jr) (05/31/90)
In article <519@synopsys.COM> stevej@synopsys.synopsys.com (Steven Jukoff) writes: | I don't know if this is disk skew or head skew or cylinder skew, etc. | What does skew mean and what is the correct answer? | | Hardware: SMS OMTI 8620 controller board attached to a Micropolis 1355. | | Both SCO and MICROPOLIS claim they do not use skew, so what's the answer? | And what is the penalty for being wrong? Skew usually means the offset between sector zero on one cylinder and the next. No penalty for being wrong, but some performance gain for being right. To be conservative figure the # of sectoers per track divided by seven. This is a "magic number" which is not optimal but usually improves the cylinder to cylinder time by about 80%. -- bill davidsen - davidsen@sixhub.uucp (uunet!crdgw1!sixhub!davidsen) sysop *IX BBS and Public Access UNIX moderator of comp.binaries.ibm.pc and 80386 mailing list "Stupidity, like virtue, is its own reward" -me