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...

Alexander Motin mav at
Mon Jul 13 05:17:54 UTC 2009

Carlos A. M. dos Santos wrote:
> On Fri, Jul 10, 2009 at 5:31 AM, Scott Long<scottl at> wrote:
>> Poul-Henning Kamp wrote:
>>> In message <200907100818.n6A8I8p1011853 at>, 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.

Alexander Motin

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