Date: Sun, 25 Jan 1998 19:04:13 +1100 From: Bruce Evans <bde@zeta.org.au> To: dburr@POBoxes.com, gibbs@narnia.plutotech.com Cc: scsi@FreeBSD.ORG Subject: Re: Minor annoyances with ZIP Plus Message-ID: <199801250804.TAA12845@godzilla.zeta.org.au>
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>>["normal" errors for zip disks] >This isn't the case. FreeBSD was being silly in asking for the optional, >rigid geometry page, which the IOMega guys chose not to implement. Since >FreeBSD stopped using physical geometry to "optimize" disk I/O (which >doesn't work on the ZBR drives of today), Actually, FreeBSD only stopped using the (possibly-non-physical) geometry in the disk label as a default for newfs. This changed about 3 years ago (before 2.0.5 was released). >asking for the rigid geometry >wasn't buying us anything and the code was recently changed to use the >information returned by the Read Capacity command instead. This hasn't actually changed (at least in the current sd driver). All that changed recently is that Read Capacity is now used to determine the sector size. Read Capacity has always been used to determine the disk size, and Mode Sense of the rigid geometry page has always been used to initialize default values for the geometry in the dummy label for the whole disk. If there is a valid DOS partition on the disk, as is normally(?) the case for new zip disks, then these default values are not used. In any case, the geometry in the dummy label for fdisk is only used by fdisk and sysinstall. Initialization of disk labels normally involves copying the geometry reported by fdisk to the labels, where it is normally not used because of the 3 year old hack to newfs. Summary: everything just works, but the lowest layer is too verbose and the highest layer (newfs) is too smart. Bruce
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