Re: OT] Joerg Schilling flames Linux on his Blog

From: Lennart Sorensen
Date: Tue May 31 2005 - 14:13:58 EST


On Tue, May 31, 2005 at 06:59:01PM +0200, Gerd Knorr wrote:
> Not really. Yes, it runs on different operating systems. But to send
> the SCSI commands to the device you have OS-specific code in there,
> simply because it's handled in different ways on Solaris / Linux /
> whatever OS. You could make the device addressing OS-specific as well
> instead of expecting everyone in the world follow the Solaris model,
> that would make life a bit easier for everyone involved.
>
> Addressing IDE devices (try to get a real SCSI burner these days)
> using scsi host+target+lun is sort-of silly IMHO ...

Well I remember the first time I saw devfs running, I thought "Wow
finally I have a way to find the disc that is scsi id 3 on controller 0
even if I add a device at id 2 after setting up the system", something
most unix systems have always had, but linux made hard (you had to
somehow figure out which id mapped to which /dev/sd* entry, which from a
users perspective wasn't trivial, and of course keeping your fstab in
sync with the mapping was a pain).

I think sysfs can do it too, although I haven't looked to much at sysfs
yet.

For IDE devices the /dev entry always mapped to a specific device
(modulo your ide drivers loading in a consistant order, but scsi host
controller load order has the same issue). Scsi just assigned /dev
entries in the order devices were discovered. In some ways it is handy
to know your first scsi drive is sda if you are doing raid1 or something
and a drive dies, but on the other hand it is annoying that drives move
around if you add drives with a lower id than your existing drives.
Having both would be preferable.

I don't know if the ide or scsi method is currently more sane, but it
sure would be nice to have a consistent behaviour between the two.

Len Sorensen
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