Re: Using the ATAPI/CAM Driver

> From: Jeff Elkins <bsd_at_elkins.org>
> Date: Sun, 8 Feb 2004 16:56:17 -0500
> Sender: owner-freebsd-current_at_freebsd.org
> 
> I've enabled the ATAPI/CAM driver in my kernel under freebsd 5.2 - this has
> given me two devices: /dev/cd0 and /dev/cd1. Thus far, I'm able to burn
> CDs/DVDs but I am having trouble mounting them (as root).
> 
> If I issue the command: mount /cdrom or mount -t cd9660 /dev/cd0 /cdrom I
> get the message:  cd9660: /dev/cd0: Device not configured
> 
> 
> However, if I comment out the /dev/cd devices in fstab and enable the acd
> devices:
> 
> /dev/acd0               /cdrom cd9660   ro,noauto       0       0
> /dev/acd1               /cdrom1 cd9660 ro,noauto        0       0
> #/dev/cd0               /cdrom cd9660   ro,noauto       0       0
> #/dev/cd1               /cdrom1 cd9660 ro,noauto        0       0
> 
> I'm able to mount w/o problems.

I suspect it's a timing issue. The ATAPICAM driver does not create the
cd devices until quite a while (about 10 seconds) after the disc is
inserted. And there is no CD device when the drive is empty/open. This
leads to a variety of annoyances, especially if you are using a tool
that assumes too much, such as the permanent presence of the device so
that its status can be checked.

I really wish that the /dev/cdN devices were always present if the
physical drive was present!
-- 
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman_at_es.net			Phone: +1 510 486-8634