A few weeks ago I asked for help formatting a Wren VII.  If you think
that there is even a slight possibility of getting one of these hummers
in your shop, I would suggest that you save this summary; it will save 
you a lot of time watching a disk format.
Original Post:
> Has anyone had success formatting a Wren VII (1.2 GB)
> connected to a SS1 running 4.0.3c MUNIX?  If so, please 
> contact me via email.
There were two problems with the format process.  1) I didn't know
what parameters to use and 2) when I did come up with some, the
format would not run to completion (or so it seemed).
Problem 1) Solution:
>From  Guy Turcotte, turcotte@asterix.drev.dnd.ca
> Here are the parameters that we used to format our CDC Wren VII. Those
> info come from the format.dat file of SunOS 4.1 beta:
> 
> disk_type = "CDC Wren VII 94601-12G" \
> 	: ctlr = MD21 : fmt_time = 4 \
> 	: cache = 0x11 : trks_zone = 15 : asect = 5 : atrks = 30 \
> 	: ncyl = 1703 : acyl = 2 : pcyl = 1931 : nhead = 15 : nsect = 80 \
> 	: rpm = 3600 : bpt = 31410
> 
and, from Bob Kusumoto, kusumoto@chsun1.uchicago.edu
> I used the following driver:
> 
> disk_type = "CDC Wren VII 94601-12G" \
> 	: ctlr = MD21 : cache = 0x11 \
> 	: ncyl = 1925 : acyl = 2 : pcyl = 1931 : nhead = 15 : nsect = 70 \
> 	: rpm = 3600 : bpt = 41301
> 
> since the format command didn't work, I left the the parameter for
> fmt_time.  Using this driver, I came up with 2021250 0.5K blocks.  the
> ncyl was suppose to be 6 less than pcyl, 2 for acyl and 4 for the MD21
> controller, so there's little incentive to increase ncyl.  You can try
> increasing the nsect parameter (up to roughly 80) to get a little more
> out, but I took a safe route.  Don't worry about the partition info, you
> can enter it in the partition menu and its more malliable that way.
> Partition c should be set to 0 and 1925/0/0.
I used the latter because some documentation accompanying the disk stated
that it should be 1.035 GB formatted (1925*15*70*512 = 1.035 GB).
Problem 2) Solution:
>From Doug Neuhauser, doug@seismo.gps.caltech.edu and 
     Per Westerlund, perw@holtec.se
(Doug)
>> A few weeks ago I posted a request for information on formatting a Wren 7
>> 1.2 GB disk drive on either a 4/280 or SS1.  The vender that was supplying my
>> drives finally admitted that they couldn't format on either machine due to
>> a "timeout".
        .
        .
        .
(Per)
> I just wanted to add that it is possible to format a drive even you have
> the timeout problem, I have done it myself.  Remember that the timeout
> problem is a problem in the driver, the disk formats as it should.
> 
> Run it this way:
> 
> 	Run format, and start the formatting.
>
> 	After a while there is a message about a timeout, and that
> 	the format failed.  Don't touch anything, just wait!
> 
> 	After a while more, there is a message about an unsolicited
> 	reconnnect or something like it.  That is the drive trying to 
> 	say that the format is finished.  (I am assuming that nothing
> 	strange is happening during the format.  Most errors are
>   	parameter errors and those are usually caught immediately.)
> 
> 	Now, the drive is formatted.  Proceed as usual with analysing,
> 	labelling etc.
> 
> 
This is exactly what happened in my case and, indeed, the disk seems
to be formatted correctly.
Thanks to Guy, Bob, Doug, Per, and others who sent information.
Chris
franz@asuvax.eas.asu.edu
This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:05:57 CDT