On 2016-03-09 16:50, hb wrote:
On 03/09/2016 09:53 AM, Johnny Billquist wrote:
Do VMS and ODS-2 really try to figure out a geometry per disk for MSCP
disks???
The ODS2 utility needs to "mount" the disk. I know nothing, but ODS-2 on
VMS probably only cares about LBNs and VBNs (and on on-disk data
structures). It is the mount utility which knows or needs to know the
geometry, to do the geometry based search for alternate home blocks
(there is also a non-geometry based search algorithm). And the mount
utility probably uses the same code as the init utility, which writes
the alternate home blocks. And both probably request the information
from some other (driver) code level.
Right. But I would have assumed that VMS would just create some fake
concept of what the geometry is for an MSCP disk, since it don't really
make sense to try and figure out the geometry in the first place. Or at
least that is my understanding.
There is no guarantee that there even is any "sane" geometry.
Johnny
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