On November 16 2002, "Kevin F. La Barre" wrote:

[deleted]

>  > amlabel bu1 BU100 slot 0
> amlabel: could not load slot "0": open: /dev/ch0: Permission denied
> 
> 
> Running chg-scsi directly has a similar effect:
> 
>  > /usr/local/libexec/chg-scsi -slot 0
> chg-scsi: open: /dev/ch0: Permission denied
> <none> open: /dev/ch0: Permission denied

[deleted]

I think you are running into a device naming vs. CAM (the FreeBSD SCSI
layer) issue.  chg-scsi tries to use CAM to talk to the changer (and
tape drive) directly if possible.  I suspect the error message is a
red herring, complaining about the wrong thing.  Unfortunately, your
configuration doesn't give it enough information to complain about the
"right thing" :)

> ** chg-scsi.conf **
> 
> number_configs  1
> eject           1       # Tapedrives need an eject command
> sleep           25      # Seconds to wait until the tape gets ready
> cleanmax        10      # How many times could a cleaning tape get used
> changerdev      /dev/ch0

[From a different message (<5.1.0.14.2.20021117131507.03a83eb0 AT mail.infidati 
DOT com>)]:

> sa0 at ahc0 bus 0 target 2 lun 0
> sa0: <DEC TZ885 CC34> Removable Sequential Access SCSI-2 device
> sa0: 10.000MB/s transfers (10.000MHz, offset 15)
> Mounting root from ufs:/dev/ad0s1a
> ch0 at ahc0 bus 0 target 2 lun 1
> ch0: <DEC TZ Media Changer CC34> Removable Changer SCSI-2 device
> ch0: 10.000MB/s transfers (10.000MHz, offset 15)
> ch0: 5 slots, 1 drive, 1 picker, 0 portals

I think you should set changerdev to "0:2:1".

> #
> # Next comes the data for drive 0
> #
> config          0
> drivenum        0
> dev             /dev/nsa0       # the device that is used for the tapedrive 0

You should also specify "scsitapedev 0:2:0" (leave the dev line in there 
though).

"chg-scsi -genconf" will scan the SCSI buses and generate a reasonable
config file to stdout.  You will need to run that as root.

Once you've altered the chg-scsi config file, you can then fix the 
permission problems that it is trying to report.  Use "camcontrol devlist"
to find the names of the CAM pass-through devices associated with the
changer and drive (you'll need to be root):

On my system, the output looks like this:

  iori# camcontrol devlist
  <Quantum DLT4000 CC1E>             at scbus0 target 4 lun 0 (pass0,sa0)
  <Quantum DLT4000 D782>             at scbus0 target 5 lun 0 (pass1,sa1)
  <BHTi Quad 7 4.25>                 at scbus0 target 6 lun 0 (pass2,ch0)
  <SEAGATE ST34555W 0930>            at scbus1 target 1 lun 0 (pass3,da0)

Look for the "passX" corresponding to your drive and changer (pass0, pass1,
and pass2 in my case). I think you'll need to make sure that /dev/passX are
group writable by operator.  Of courese, /dev/ch0 and /dev/nsa0 should
also be writable by group operator so you can move tapes "by hand" and
taper can write the dump data to tape (the "dev" from the chg-scsi config
file will be passed to amanda as the tape device to write on).

Note that I'm not currently using chg-scsi on my FreeBSD system but I have
in the past.  I'm dredging these details up from dim memories and my old
config files.  Your mileage may vary, etc.

-Ben

-- 
Benjamin Lewis <bhlewis AT purdue DOT edu>
Database Analyst/Programmer
Instructional Computing Services - Computing Accounts
Purdue University