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Path: sserve!manuel!munnari.oz.au!sgiblab!spool.mu.edu!news.nd.edu!mentor.cc.purdue.edu!noose.ecn.purdue.edu!sparkyfs.erg.sri.com!csl.sri.com!csl.sri.com!usenet From: caveh@spartacus.csl.sri.com (Caveh Jalali) Newsgroups: comp.unix.bsd Subject: Re: [386bsd]Wanted:PC Diagnostic reporting bad BLOCKS (not track/head) Date: 5 Oct 92 18:07:21 Organization: Kernel Labs. NOT! Lines: 40 Message-ID: <1aqootINNo3l@roche.csl.sri.com> References: <1992Oct1.173109.5869@csx.cciw.ca> NNTP-Posting-Host: spartacus.csl.sri.com In-reply-to: u009@csx.cciw.ca's message of Thu, 1 Oct 1992 17:31:09 GMT In article <1992Oct1.173109.5869@csx.cciw.ca> u009@csx.cciw.ca (G. Stewart Beal) writes: the interleaving will not change your block number or sector numbering. it does determine their physical order on the disk, but not their sector numbers. each sector has it's sector number recorded on the disk (ie. "soft sectoring"). i have the same problem that you describe. all the formatters i've used will mark every sector on a track as bad (this can be done in the sector header) for every track that has a bad spot (sector) on it. in other words they do bad-tracking rather than bad-sectoring. BSD likes to do bad-sectoring. you will have to enumerate every bad sector in the bad144 table that corresponds to the track containing a bad sector. note that you will have to verify that your driver *correctly* supports sector remapping. the original 386BSD driver does not. i've beaten mine into submission so that it works for me. i think there are patches which claim to fix sector remapping as well. my version of wd.c is has significant changes, so i don't think i can send diffs at this point. another enhancement i made was to introduce the convention that sector #255 is a wildcard sector, such that the entire track is marked as remapped. this is somewhat consistent with the SCSI convention, but more importantly cuts down the size of your bad144 table by a factor of 17! this is significant since the table needs to be scanned (linearly right now!) for every disk transfer (generally 8K). one question i have about the current wd.c driver is whether it handles the case correctly, where a disk transfer starts on a "normal" sector, but either has a bad sector in the middle of the transfer or at the end. is the driver smart enough to split the transfer into the required 2 or 3 sub-transfers??? could someone familiar with the current driver let me know, please? 00c -- 00c -- caveh@csl.sri.com "X is not a letter, it's a sentence."