svn commit: r195534 - in head: etc/mtree include lib/libcam sbin/camcontrol share/man/man4 sys/cam sys/cam/ata sys/cam/scsi sys/conf sys/dev/advansys sys/dev/ahci sys/dev/aic7xxx sys/dev/amd sys/de...

[Carlos A. M. dos Santos]

On Mon, Jul 13, 2009 at 2:17 AM, Alexander Motin<mav at freebsd.org> wrote:
> Carlos A. M. dos Santos wrote:
>>
>> On Fri, Jul 10, 2009 at 5:31 AM, Scott Long<scottl at samsco.org> wrote:
>>>
>>> Poul-Henning Kamp wrote:
>>>>
>>>> In message <200907100818.n6A8I8p1011853 at svn.freebsd.org>, Scott Long
>>>> writes:
>>>>
>>>>>  ATA drives are accessed via 'ada' device nodes.
>>>>
>>>> It there a particular good reason why we insist on making this
>>>> silly mistake every five years ?
>>>>
>>>> I am pretty sure you were around when Justin won friends by renaming
>>>> the SCSI disk devices ?
>>>
>>> 1. I clearly stated that the name is experimental and that a change in
>>> the future is possible.
>>
>> Well, from a user's perspective, if CD/DVD drives are to be seen as
>> 'cdX', then it would make sense that hard disks were seen as daX, as
>> already advertised by cam(4).
>
> cdX implemented by cd(4) driver in both cases uses the same SCSI command
> set. In ATA case, SCSI commands are just wrapped within ATAPI PACKET
> command. For disks, situation is completely different, as ATA disks have
> completely different command and feature set. So da(4) is a driver for SCSI
> command set devices and ada(4) is a driver for ATA command set devices.

I know, but that is the driver's perspective, not the user's perspective.


-- 
My preferred quotation of Robert Louis Stevenson is "You cannot
make an omelette without breaking eggs". Not because I like the
omelettes, but because I like the sound of eggs being broken.