Subject: NetBSD calculates sd geometry oddly?
To: None <netbsd-users@NetBSD.ORG>
From: Thor Lancelot Simon <email@example.com>
Date: 05/09/1995 20:14:16
I've noticed twice now that NetBSD sometimes decides scsi disks have less
sectors on them than other operating systems. This can be a huge pain when
trying to convert disks labelled on other operating systems.
Typically I have to either use the translated label, dump all the
filesystems, and restore them, or patch NetBSD disklabel to allow a
label to be written containing sectors that disklabel thinks are off
the end of the disk.
NetBSD seems to ask the drive for its geometry and multiply values to
get the total number of sectors on the disk. Often this is some
relatively small number of sectors less than the actual total. Is the
consensus that this is nonetheless the right thing to do, even when
the reported geometries of SCSI disks are often only vaguely related