On 04.08.2010, at 19:53, Anthony Liguori wrote: > On 08/04/2010 12:37 PM, Avi Kivity wrote: >> On 08/04/2010 08:27 PM, Anthony Liguori wrote: >>> On 08/04/2010 12:19 PM, Avi Kivity wrote: >>>> On 08/04/2010 08:01 PM, Paolo Bonzini wrote: >>>>> >>>>> That's another story and I totally agree here, but not reusing /dev/sd* >>>>> is not intrinsic in the design of virtio-blk (and one thing that Windows >>>>> gets right; everything is SCSI, period). >>>>> >>>> >>>> I don't really get why everything must be SCSI. Everything must support >>>> read, write, a few other commands, and a large set of optional commands. >>>> But why map them all to SCSI? What's the magic? >>> >>> Because that's what real hardware with only a few rare exceptions. >>> >> >> I thought that IDE was emulated as SCSI even when it wasn't. But I guess >> now with SATA you're right. > > IDE -> EIDE -> ATA -> SATA > > ATA can encapsulate SCSI commands via ATAPI which gives you the ability to > have ATA based CD-ROMs among other things. > > I don't believe that SATA actually uses SCSI commands for read/write > operations
It doesn't. In fact, it's basically just a wrapper around the normal ATA commands - even for read/write. Plus some additional SATA only commands for parallel read/write. > but I think Linux exposes SATA drivers as SCSI anyway. Yup. That's what libata does. Even works with PATA drives. But this is a purely Linux internal thing. Alex
