CAM 2TB array support available

[Kenneth D. Merry]

There are patches against -current (from 4/26/2003) here:

http://people.freebsd.org/~ken/cam.2TB.20030427

to allow the da(4) driver to talk to arrays larger than 2TB.

This enables READ(16), WRITE(16) and READ CAPACITY(16) support.

Note that that patch bumps CAM_VERSION, so you'll need to recompile libcam,
camcontrol and any ports that talk to CAM.  (e.g. cdrecord, cdda2wav, xmcd,
etc.)

If you have a device that supports 16 byte commands, but you don't have 2TB
or more worth of disk space on it, you can still try out the 16 byte
commands by increasing the minimum command size.  For da0, you'd do:

sysctl -w kern.cam.da.0.minimum_cmd_size=16

DO NOT try that on your boot disk unless you're sure it supports 16 byte
commands.  Otherwise you'll have a fine time trying to crank the value back
down when you can't get to the sysctl binary because you're trying to use
16 byte reads to read it. :)

Please send me feedback if you test these patches out.  I'd also like
testers with normal SCSI hardware.  Your disks should work as before.  In
particular, make sure the disk capacity information that is printed out
via dmesg for each disk is the same before and after the patch.

I plan on checking this in before the 5.1 freeze.

Ken
-- 
Kenneth Merry
ken at kdm.org