'camcontrol rescan all' does not find the attached tape drive

Tue May 2 20:59:11 UTC 2006

Hello list.

Using camcontrol, I cannot get freebsd 6.1-RC1 to recognize an attached
tape drive.  Is this normal?

If the machine boots with the tape drive turned off, I cannot get the tape
drive to be recognized after I turn the tape drive on.

# camcontrol rescan 1
Re-scan of bus 1 was successful
# camcontrol rescan all
Re-scan of bus 0 was successful
Re-scan of bus 1 was successful
# camcontrol devlist -v
scbus0 on asr0 bus 0:
<ADAPTEC RAID-5 3B0A>              at scbus0 target 0 lun 0 (da0,pass0)
<SUPER GEM318 0>                   at scbus0 target 6 lun 0 (ses0,pass1)
<  >                               at scbus0 target -1 lun -1 ()
scbus1 on asr0 bus 1:
<  >                               at scbus1 target -1 lun -1 ()
scbus-1 on xpt0 bus 0:
<  >                               at scbus-1 target -1 lun -1 (xpt0)

If the machine boots up while the tape drive is attached and powered up,
the tape drive is recognized.

# camcontrol devlist
<ADAPTEC RAID-5 3B0A>              at scbus0 target 0 lun 0 (da0,pass0)
<SUPER GEM318 0>                   at scbus0 target 6 lun 0 (ses0,pass1)
<HP Ultrium 2-SCSI S24D>           at scbus1 target 6 lun 0 (sa0,pass2)

Here are some more details about my setup.

machine:

- supermicro super server 6013P-8 with zero channel raid controller
- SMP hardware, UP kernel with ASR_COMPAT
- FreeBSD name 6.1-RC FreeBSD 6.1-RC #1: Fri Apr 21 16:09:23 MDT 2006
- Adaptec AIC-7902 Dual-Channel Ultra-320 Controller
- Adaptec 2015S ZCR Card

relevant dmesg data:

asr0: <Adaptec Caching SCSI RAID> mem 0xf8300000-0xf83fffff,0xfb000000-0xfbffffff,0xfc000000-0xfdffffff irq 30 at device 3.0 on pci3
asr0: [GIANT-LOCKED]
asr0: ADAPTEC 2015S FW Rev. 3B0A, 2 channel, 256 CCBs, Protocol I2O

sa0 at asr0 bus 1 target 6 lun 0
sa0: <HP Ultrium 2-SCSI S24D> Removable Sequential Access SCSI-3 device
ses0 at asr0 bus 0 target 6 lun 0
ses0: <SUPER GEM318 0> Fixed Processor SCSI-2 device
ses0: SAF-TE Compliant Device
da0 at asr0 bus 0 target 0 lun 0
da0: <ADAPTEC RAID-5 3B0A> Fixed Direct Access SCSI-2 device
da0: Tagged Queueing Enabled
da0: 70006MB (143372288 512 byte sectors: 255H 63S/T 8924C)

When I power down and disconnect the tape drive /var/log/messages receives
the following.

Apr 26 13:57:20 name kernel: (sa0:asr0:1:0:0): lost device
Apr 26 13:57:20 name kernel: (sa0:asr0:1:0:0): removing device entry

So I reboot, and try a different disconnect method.

# camcontrol stop sa0
Unit stopped successfully
# camcontrol devlist
<ADAPTEC RAID-5 3B0A>              at scbus0 target 0 lun 0 (da0,pass0)
<SUPER GEM318 0>                   at scbus0 target 6 lun 0 (ses0,pass1)
<HP Ultrium 2-SCSI S24D>           at scbus1 target 6 lun 0 (sa0,pass2)

Then I power off the tape unit and attach a new unit (attach scsi cable,
power cable, then power on the unit).

# camcontrol tur sa0 -E -C 4 -v
error sending test unit ready: Device not configured
(pass2:asr0:1:6:0): TEST UNIT READY. CDB: 0 0 0 0 0 0
(pass2:asr0:1:6:0): CAM Status: CCB request is in progress

/var/log/messages got the following 2 lines as soon as I launched
camcontrol:

Apr 26 15:32:27 name kernel: (sa0:asr0:1:6:0): lost device
Apr 26 15:32:27 name kernel: (sa0:asr0:1:6:0): removing device entry

# camcontrol rescan pass2
Re-scan of bus 0 was successful

This is a problem as the tape drive (pass2) was on bus 1.  Granted, pass2
was pointing to sa0:asr0:1:6:0 and the device that is now attached is
connected via asr0:1:0:0.

adamu010# camcontrol rescan all
Re-scan of bus 0 was successful
Re-scan of bus 1 was successful
# camcontrol devlist
<ADAPTEC RAID-5 3B0A>              at scbus0 target 0 lun 0 (da0,pass0)
<SUPER GEM318 0>                   at scbus0 target 6 lun 0 (ses0,pass1)
# camcontrol rescan 1:0:0
Re-scan of 1:0:0 was successful
# camcontrol devlist
<ADAPTEC RAID-5 3B0A>              at scbus0 target 0 lun 0 (da0,pass0)
<SUPER GEM318 0>                   at scbus0 target 6 lun 0 (ses0,pass1)
# camcontrol reset 1
Reset of bus 1 was successful
# camcontrol rescan 1
Re-scan of bus 1 was successful
# camcontrol devlist 1
<ADAPTEC RAID-5 3B0A>              at scbus0 target 0 lun 0 (da0,pass0)
<SUPER GEM318 0>                   at scbus0 target 6 lun 0 (ses0,pass1)

The drive documentation states that the drive's auto-termination is only
in effect when the drive is powered on.  Does that mean I have an
unterminated bus when the tape drive is off?  Perhaps the aic7902
auto-terminates scbus1?  How does termination influence what camcontrol
sees?  The tape drive is not detected without a reboot.  Despite the fine
man page for camcontrol and several examples provided by google of other
users using camcontrol to successfully reattach devices, I cannot do it.
I assume I have done something wrong, like misunderstanding how scsi
devices and/or termination function.  Can anyone point out what I am doing
wrong and/or tell me how to change tape drives without rebooting my box?

Thank you for any help!

Adam

ps:  Please CC me as I am not subscribed to this list.  TIA!