From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Bunk Subject: Re: /dev/sd* Date: Thu, 10 Aug 2006 00:18:57 +0200 Message-ID: <20060809221857.GG3691@stusta.de> References: <1155144599.5729.226.camel@localhost.localdomain> <20060809212124.GC3691@stusta.de> <1155160903.5729.263.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mailout.stusta.mhn.de ([141.84.69.5]:18450 "HELO mailout.stusta.mhn.de") by vger.kernel.org with SMTP id S1751400AbWHIWTB (ORCPT ); Wed, 9 Aug 2006 18:19:01 -0400 Content-Disposition: inline In-Reply-To: <1155160903.5729.263.camel@localhost.localdomain> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org On Wed, Aug 09, 2006 at 11:01:43PM +0100, Alan Cox wrote: > Ar Mer, 2006-08-09 am 23:21 +0200, ysgrifennodd Adrian Bunk: > > It might be a bit out of the scope of this thread, but why do some many > > subsystems use the /dev/sd* namespace? > > > > Real SCSI devices use it. > > The USB mass storage driver uses it. > > USB storage is real SCSI. Real SCSI for a developer, for a user it's USB. And things become even more confusing considering that the drive might show up as /dev/sda or /dev/uba depending on the driver used. > > libata uses it. > > > > I'd expext SATA or PATA devices at /dev/hd* or perhaps at /dev/ata* - > > but why are they at /dev/sd*? > > ATA uses the top half of the scsi stack so ends up using the top layer > scsi drivers. Its probably more efficient than writing new driver > clones, especially as non disk ATA is also real SCSI (or very close). You are talking about kernel<->kernel and kernel<->hardware interfaces. I'm more concerned about the kernel<->userspace interface. > You can use /dev/ata if you want - its just a udev problem ;) Or by adding some manual links if using a static /dev. But I'm still not getting the point why the /dev/sd* namespace has to be used. > Alan cu Adrian -- "Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed