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- Newsgroups: comp.unix.bsd
- Path: sparky!uunet!think.com!spool.mu.edu!agate!tfs.com!tfs.com!julian
- From: julian@tfs.com (Julian Elischer)
- Subject: Re: [386BSD] Disklabel for MAXTOR LXT340S
- Message-ID: <1992Dec12.100620.16224@tfs.com>
- Organization: TRW Financial Systems
- References: <1992Dec10.080231.10747@email.tuwien.ac.at>
- Date: Sat, 12 Dec 1992 10:06:20 GMT
- Lines: 108
-
- In article <1992Dec10.080231.10747@email.tuwien.ac.at> mbirgmei@email.tuwien.ac.at (Martin BIRGMEIER) writes:
- >Hello netters,
- >
- >could those who know please tell me the geometry and other pertinent
- >data (disklabel etc) of the following drive type which I'm using under
- >386bsd:
- >
- >MAXTOR LXT340S 6.20
- >
- >Julian's SCSI driver reports 322MB, cyls 1546, heads 7, secs 61,
- >bytes/sec 512 - which yields according to my poor knowledge of algebra
- >1546 * 7 * 61 / 2 / 1024 MB of disk space, equal to 322.33496 MB (which
- >coincides with the first number given - so far so good).
- >
- >But why then did the default installation (install.fs) create the following
- >disklabel:
- >
- ># /dev/ras0d:
- >type: SCSI
- >disk:
- >label:
- >flags:
- >bytes/sector: 512
- >sectors/track: 32
- >tracks/cylinder: 64
- >sectors/cylinder: 2048
- >cylinders: 324 <=========================== (!)
- It used the BIOS's idea of the geometry which is different.
- (The adaptec sets it up to LOOK LIKE 32sec, 64heads, 324CYL)
-
- in fact since the disk MAY have Zone recording we may BOTH be wrong!
- in taht case teh number of sectors per cyl (I give an average)
- MIGHT be as high as 61.9999999 but I can only use the integer
- 61.
- This would give an actual size of 335.4MB
- ( must report a size that gives an integer number of cyls
- according to the (obviously ficticious) figures I have
- calculated. therefore I 'lose' about 2MB.)
- sorry.. (there may be a better way)
-
- >rpm: 3600
- >interleave: 0
- >trackskew: 0
- >cylinderskew: 0
- >headswitch: 0 # milliseconds
- >track-to-track seek: 0 # milliseconds
- >drivedata: 0
- >
- >3 partitions:
- ># size offset fstype [fsize bsize cpg]
- > a: 653312 0 4.2BSD 1024 8192 16 # (Cyl. 0 - 318)
- > b: 10000 654653 unused 0 0 # (Cyl. 319*- 324*)
- > c: 665153 0 unused 0 0 # (Cyl. 0 - 324*)
- >
- >Question: Why are there those gaps between partitions a and c, and why is
- >there a gap between the end of b and the assumed and of the disk as defined
- >by partition c?
- no idea.. (That's the install prog at work)
-
- >
- >I manually repartitioned the whole thing with the following disklabel (nice
- >exercise getting used to the quirks of rdump and rrestore :-)):
- >
- ># /dev/ras0d:
- >type: SCSI
- >disk:
- >label:
- >flags:
- >bytes/sector: 512
- >sectors/track: 32
- >tracks/cylinder: 64
- >sectors/cylinder: 2048
- >cylinders: 322
- >rpm: 3600
- >interleave: 1
- >trackskew: 0
- >cylinderskew: 0
- >headswitch: 0 # milliseconds
- >track-to-track seek: 0 # milliseconds
- >drivedata: 0
- >
- >7 partitions:
- ># size offset fstype [fsize bsize cpg]
- > a: 40960 0 4.2BSD 1024 8192 16 # (Cyl. 0 - 19)
- > b: 51200 40960 swap # (Cyl. 20 - 44)
- > c: 659456 0 unused 0 0 # (Cyl. 0 - 321)
- > d: 659456 0 unused 0 0 # (Cyl. 0 - 321)
- > g: 567296 92160 4.2BSD 1024 8192 16 # (Cyl. 45 - 321)
- >
- >Is this a good thing to do? Obviously, I'm still missing some vital
- >data. For one, I changed interleave from 0 to 1, which seems quite
- >obvious. But what should I fill into the remaining unknown fields
- >(disk, label, flag, rpm, trackskew, cylinderskew, headswitch,
- >track-to-track seek, drivedata)? I assume that the skews are 0 (since
- >the drive does internal translation anyway), what about the others? Or
- >is it possible to use the drive in untranslated mode (don't think with
- >a SCSI)?
- >
- >So, any help (and numbers) would greatly be appreciated!
- >
- >Thanks in advance,
- >
- >Martin Birgmeier
- >Technical University of Vienna
- >Dept. of Comm. Engr.
- >Austria
-
-
-