[comp.sys.next] du output dosen't match drive spec *or* scsimodes...

zazula@uazhe0.physics.arizona.edu (RALPH ZAZULA) (03/06/91)

Can someone help me out here?

I have a Micropolis 1578-15 drive.  The manufacturer says that it is
382Meg unformatted, 338.1Meg formatted.  When I boot my machine, it
says MICROP 1578-15 313Meg.  First I thought that the other 25Meg was
either bad sectors and/or reserved by the file system.  But, if I look
at df, I get the following: 

	kbytes    used   avail capacity
	308891  226593   51408    82% 

Now it appears that 313Meg went down to 308.8Meg.  But, add up
used+avail=278Meg.  This is getting worse.  I'm missing 60Meg (or
so it appears).  Now, scsimodes tells me:

scsimodes /dev/rsd0a
SCSI information for /dev/rsd0a
Drive type: MICROP 1578-15
512 bytes per sector
36 sectors per track
15 tracks per cylinder
1224 cylinder per volume (including spare cylinders)
1 spare sectors per track
45 alternate tracks per volume
639449 usable sectors on volume

Doing the math: spare+alternate = 8.3Meg
	        usable = 327.4Meg

It dosen't seem like any of these numbers match up!!!!

Anybody have any clues??  I'm willing to reformat to gain anything
over 5-10Meg!

Thanks,
Ralph



   |----------------------------------------------------------------------|
   | Ralph Zazula                               "Computer Addict!"        |
   | University of Arizona                 ---  Department of Physics     |
   |   UAZHEP::ZAZULA                            (DecNet/HEPNet)          |
   |   zazula@uazhe0.physics.arizona.edu         (Internet)               |
   |----------------------------------------------------------------------|
   |   "You can twist perceptions, reality won't budge."  - Neil Peart    |
   |----------------------------------------------------------------------|

rpruess@yoyo.weeg.uiowa.edu (Rex Pruess) (03/06/91)

In article <5MAR91203419@uazhe0.physics.arizona.edu> zazula@uazhe0.physics.arizona.edu (RALPH ZAZULA) writes:

 > Can someone help me out here?
 >
 > I have a Micropolis 1578-15 drive.  The manufacturer says that it is
 > 382Meg unformatted, 338.1Meg formatted.  When I boot my machine, it
 > says MICROP 1578-15 313Meg.  First I thought that the other 25Meg ...

Sure.  This issue has been bounced around the past week or so in this
group under the obscure subject "Misc questions".  The notes are rather
lengthy.  In case you can't find those notes, I'll mail a couple of them
to you.  I believe the notes will answer your questions.
--
Rex Pruess, Weeg Computing Center, Univ of Iowa, Iowa City, IA 52242
rpruess@umaxc.weeg.uiowa.edu (NeXTmail)               (319) 335-5452