Re: Help - SCSI passthrough ioctl calls vs. sd/sg devices

From: John-Paul Stewart (jpstewart_at_binaryfoundry.ca)
Date: 04/22/04 

Date: Thu, 22 Apr 2004 10:47:51 -0400

L wrote:
>
> What should we do if we need to 'mount' a file system on a disk and also
> need to issue SCSI passthrough ioctl calls to the same disk? Maybe we
> should use both sd and sg (i.e. mount the file system to /dev/sda1, and
> issue SCSI passthrough ioctl calls to /dev/sg0 that maps to the same
> disk/lun)?

Can you clarify what you're trying to accomplish here? Under normal
operation, one accesses a SCSI disk as /dev/sdX. *All* normal
operations are handled that way.

The *only* time I've ever accessed a SCSI disk through the /dev/sgX
interface was to run a diagnostic program from the manufacturer on a
faulty drive.

I don't mean to be rude, but I get the impression that you fall into one
of two categories: 1) you're a newbie trying to do something you don't
need to do with the /dev/sgX devices, or 2) you're trying to do
something rather advanced (like disk diagnostics) without understanding
the basics of the SCSI drivers first.

> I was told 'mount' doesn't work on sg devices, right?

Right.

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