[Info-vax] Need help mounting shadow set

[Tom Adams]

On Oct 6, 7:08 am, VAXman-  @SendSpamHere.ORG wrote:
> In article <0083cd72$0$30078$c3e8... at news.astraweb.com>, JF Mezei <jfmezei.spam... at vaxination.ca> writes:
>
> >Just a question out there...
>
> >Would it be possible to do a low level format of the drive and somehow
> >give it parameters to make those missing 480 blocks appear ?
>
> >Or would it be possible to dismount the already populated drive, and set
> >something in it that would remove 480 blocks from its stated capacity
> >which, when mounted, would then allow the new disk to be included in a
> >showdow set ?
>
> I had to go back and sift through the original quoted-pukeable post to
> extract this:
>
> Disk $1$DKA100: (EESN), device type COMPAQ ST32171W,...
>
> Total blocks        4110000    Sectors per track        165
> Total cylinders        4982    Tracks per cylinder        5
>
> Disk DSA0:, device type DEC RZ1BB-CS,...
>
> Total blocks        4110480    Sectors per track         86
> Total cylinders        2988    Tracks per cylinder       16
>
> There are two fairly disparate geometries between the two drives.  It
> might be possible to modify firmware to make the larger DEC RZ1BB-CS
> not report 480 blocks but it would be far easier to use modern volume
> shadowing which permits HBVS of disparate drives.
>
> There's more info on the ST32171W here:http://www.seagate.com/support/disc/manuals/scsi/67491d.pdf
>
> The only sage advice that I can offer here is: When purchasing drives,
> purchase spares.
> --
> VAXman- A Bored Certified VMS Kernel Mode Hacker    VAXman(at)TMESIS(dot)ORG
>
>  http://www.quirkfactory.com/popart/asskey/eqn2.png
>
>   "Well my son, life is like a beanstalk, isn't it?"

I notice an extra jumper on the "new" smaller disk. I was tempted to
take it off an see if it became like the larger disks.  I could still
do the experiment, but I have more productive things to do.

I kept my "bad" disk in the shadow set.  It is currently showing no
errors.  I think the "bad" disk is only a problem when a bad block
gets located in a trailing block of a file where the sun don't shine.
When that happens, it logs an error when I put it in the shadowset or
when I run ANAL/DISK/SHAD.  Or, so I have been told here.  I guess its
a bug in the shadowing software that does not handle the trailing
blocks consistently.