On Thu, Aug 10, 2006 at 12:18:57AM +0200, Adrian Bunk wrote: > 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. So? Users of Linux know to look for their USB storage devices in /dev/sd* because of this. > And things become even more confusing considering that the drive might > show up as /dev/sda or /dev/uba depending on the driver used. And udev causes this to be moot, as people use the /dev/disk/by-* symlinks, which are the same if they use the usb-storage or ub driver. Same thing will happen for the changes that Alan is going to do (which I think is the right thing to have happen.) > > > 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. Sure, but most distros don't have a static /dev anymore. > But I'm still not getting the point why the /dev/sd* namespace has to be > used. Because it has for USB storage devices since the 2.2 kernel. Ok, 2.3, but then quickly backported to 2.2... You want to break that userspace interface? :) thanks, greg k-h - : send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
