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SubjectRe: The advantage of modules?
On Mon, Jan 08, 2001 at 07:26:01PM +0100, Ookhoi wrote:
> > 3) Having drivers as modules means that you can remove them and
> > reload them. When I was working in an office, I had one scsi
> > controller that was a different brand (Adaptec) than the main scsi
> > controller (TekRam), and I hung a disk in a removable chasis on the
> > scsi chain in addition to a tape driver and cd-rom. When I was
> > about to go home, I would copy all of the data to the disk, unmount
> > it, and then unload the scsi device driver. I would take the disk
> > out, and reload the scsi device driver to get the tape/cd-rom. I
> > would then take the disk to my home computer. I would reverse the
> > process when I came in the morning.
>
> You don't need modules for this to work.

Quoting from drivers/scsi/scsi.c:

/*
* Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
* with "0 1 2 3" replaced by your "Host Channel Id Lun".
* Consider this feature BETA.
* CAUTION: This is not for hotplugging your peripherals. As
* SCSI was not designed for this you could damage your
* hardware !
* However perhaps it is legal to switch on an
* already connected device. It is perhaps not
* guaranteed this device doesn't corrupt an ongoing data transfer.
*/

so my take is unless you explicitly use hotplug devices (I wasn't), that it is
much safer to unload the driver, unattach/attach scsi devices, and then reload
the driver (which will scan the scsi bus for devices), which you need modules
for.

--
Michael Meissner, Red Hat, Inc. (GCC group)
PMB 198, 174 Littleton Road #3, Westford, Massachusetts 01886, USA
Work: meissner@redhat.com phone: +1 978-486-9304
Non-work: meissner@spectacle-pond.org fax: +1 978-692-4482
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