[aus.sun-works] Wren V partitioning

andrew@megadata.mega.oz.au (Andrew McRae) (03/26/91)

I know this has been discussed previously, and perhaps
someone has a summary that they can send me, but I am having
continual problems with a Wren V on a Sparcstation 1+ (SunOS 4.1.1) that
seem to relate back to a partitioning problem. The disc has been
running for a long time previously on a Sun 3/60 running 4.0.3 with no
problems.

As most of us know, the Wren V (94181-702) has variable sectors/track,
and so selecting the right format parameters is not obvious. I have
used the parameters in the 4.1.1 standard format.dat for sectors/track,
cylinders etc, but the partition data for the Wren seems entirely
wrong (e.g. partition c = 0, 639450 - 320 Meg??), so I split the
disc into three equal partitions as such:

	sd1: Emulex MD21 controller at addr f8800000, unit # 8
	1543 cylinders 15 heads 48 sectors/track
	a: 367200 sectors (510 cyls)
	   starting cylinder 0
	b: 367200 sectors (510 cyls)
	   starting cylinder 510
	c: 1101600 sectors (1530 cyls)
	   starting cylinder 0
	d: 367200 sectors (510 cyls)
	   starting cylinder 1020

Even though I should be able to access up to cylinder 1543, I get read
errors beyond 1530, hence the reduced size.

Two problems are bothering me. In the course of using the disc, and
also doing surface analysis using format, the disc is de-selecting and
timing out. More often a messages appears (approx):

sd1: incomplete read- retrying

No mention of this message in the sd man entry. BTW the disc is
running synchronous (at 4.167 Mb/s).
Performing a burn in using format and surface analysis seemed to
reduce the errors (the incomplete read errors, that is) so I suspected that
media errors were causing the message.

The other (and more serious problem) is that once three file systems
are built on the disc, strange file system problems occur which crash
the system, such as `freeing free inode'. When this occurs the file
system in question seems quite damaged in places, almost as if the other
partitions are overlapping it. When I mount two of them read only, the
problems seem to go away. Could this be caused by some partition problem?

Does anybody have the complete low-down on Wren V's, SunOS 4.1.1 etc
that they could tell me? I am attempting to get a Wren manual, but if
there are jumpers to enable modes etc, it would be good to know.

Thanks a lot (in advance).

Andrew McRae			inet:	andrew@megadata.mega.oz.au
Megadata Pty Ltd,		uucp:	..!uunet!megadata.mega.oz.au!andrew
North Ryde  2113		Phone:	+61 2 805 0899
NSW    AUSTRALIA		Fax:	+61 2 887 4847