Questions on CDC Wren IV layout...

[Steve Wampler]

We've been having some trouble with some Wren IV drives under
Ultrix 2.2, and have some conflicting information that I'm
hoping someone can clear up/explain.

Our last system adminstrator got the following information from
the vendor we bought the drives from (all model 94171-300):

	16 sectors/track
	 4 tracks/cylinder !?
      9167 cylinders/drive !?

consequently, that's how the drive tables in Ultrix have
been configured.  Because of the problems with *large* amounts
of disk errors in the past few weeks, our current system
adminstrator called CDC (I think) and got:

	40 sectors/track
	 9 tracks/cylinder
      1412 cylinders/drive

which seem more reasonable figures.  Can someone verify these
numbers for me?

Now, assuming that we've configured the drives to be 14% larger
than they actually are (hey, virtual drives, how nice!), can someone
tell me what Ultrix is going to do as the drives approach real
capacity?  I'm trying to help our sysadmin track down some bad
behavior with our disks.

Thanks for any help.  I'd prefer email, but I'll take what I can get.
-- 
	Steve Wampler
	{....!arizona!naucse!sbw}