On Wednesday 20 November 2002 17:10, Damon Conway wrote:
>Hello all,
>I've been wrestling with chg-scsi and my Quantum changer all day. 
> Here are the specs:
>
>Red Hat 8.0 w/ kernel 2.4.18
>Quantum SuperLoader SDLT 3520L
>Amanda 2.4.3
>
>If I set changerdev to /dev/sg0 and dev to /dev/nst0, I get this:
>
># sudo /usr/local/libexec/chg-scsi -info
>Can't get ElementStatus
>#
>
>I can't find anything on that error in the list archives,
> searching Google, or looking in the docs (TAPE.CHANGERS or
> FAQ-O-MATIC). According to /proc/scsi/sg/device*, /dev/sg0 is
> "QUANTUM  SuperDLT1 2A2A".  I'm assuming that the error means
> that it can't talk to the device.
>
One thing that can trip up the unwary is that, depending on the 
drive, the changer robot may be at the same bus address as the 
drive, but is lun=1 where the drive is lun=0.  Thats the case here 
at my place.

The tripup is that the stock kernel dos not AFAIK, do a "scan all 
luns" at startup, thereby missing the changer robot.  This is an 
option you may have to turn on and rebuild the kernel to make work 
if thats the case with your changer.

Also, look at /var/log/dmesg, where one should see something like 
this:
---------
[...]
SCSI subsystem driver Revision: 1.00
scsi0 : AdvanSys SCSI 3.3G: PCI Ultra: IO 0xD000-0xD00F, IRQ 0xB
  Vendor: ARCHIVE   Model: 4586XX 28887-XXX  Rev: 0420
  Type:   Sequential-Access                  ANSI SCSI revision: 02
  Vendor: ARCHIVE   Model: 4586XX 28887-XXX  Rev: 0420
  Type:   Medium Changer                     ANSI SCSI revision: 02
scsi1 : SCSI host adapter emulation for IDE ATAPI devices
  Vendor: CREATIVE  Model: CD-RW RW1210E     Rev: LCS6
  Type:   CD-ROM                             ANSI SCSI revision: 02
st: Version 20020805, bufsize 32768, wrt 30720, max init. bufs 4, 
s/g segs 16
Attached scsi tape st0 at scsi0, channel 0, id 6, lun 0
Attached scsi CD-ROM sr0 at scsi1, channel 0, id 0, lun 0
sr0: scsi3-mmc drive: 32x/32x writer cd/rw xa/form2 cdda tray
Uniform CD-ROM driver Revision: 3.12
Attached scsi generic sg1 at scsi0, channel 0, id 6, lun 1,  type 8
---------------
Note the last line above.  Same address, but different, non-zero 
lun, as the 'scsi tape st0' a few lines above it.  Use these 
detected device names in your .conf files, except of course you 
want to make the st0 into nst0 since you don't want the automatic 
rewind, never use it with amanda.

And thats my $0.02. :-)

>Since it appears that both the robot and the drive are showing up
> as the same SCSI ID, I changed changerdev to /dev/nst0, and I get
> this:
>
># sudo /usr/local/libexec/chg-scsi -info
>chg-scsi: open: /dev/nst0: Success
><none> open: /dev/nst0: Success
>#
>
>No matter what option I give to chg-scsi, I get the same output.
>
>Any ideas on what I'm doing wrong, or what I can do next to debug
> this? I've included my amanda.conf and chg-scsi.conf files below.

>Thanks,
>Damon

-- 
Cheers, Gene
AMD K6-III@500mhz 320M
Athlon1600XP@1400mhz  512M
99.19% setiathome rank, not too shabby for a WV hillbilly