[CentOS] Quantum scalar i40 tape partitions

Wed Feb 1 01:13:51 UTC 2012
David G. Miller <dave at davenjudy.org>

Xinhuan Zheng <xzheng at ...> writes:

> 
> Hi All,
> 
> I have a Quantum scalar i40 tape library. I need to configure it to TWO tape
partition libraries, e.g.,
> library_a and library_b, so that each library has its own tape drive. Then
connect this physical tape
> library to two different CentOS servers so that each server can see its own
media changer and tape drive. I
> once had a successful configuration on one host but NOT on the other. One host
sees the media changer and one
> tape drive, while the other host only sees the tape drive. After I delete tape
partitions and re-create
> them both servers are totally screwed up. This is CentOS 5.7 kernel 2.6.18-274.
> 
> On one server:
> 
> # cat /proc/scsi/scsi
> Attached devices:
> Host: scsi0 Channel: 00 Id: 00 Lun: 00
>   Vendor: HP       Model: Ultrium 5-SCSI   Rev: Z58Z
>   Type:   Sequential-Access                ANSI SCSI revision: 06
> Host: scsi0 Channel: 00 Id: 00 Lun: 01
>   Vendor: QUANTUM  Model: Scalar i40-i80   Rev: 135G
>   Type:   Medium Changer                   ANSI SCSI revision: 03
> 
> # mtx -f /dev/sg0 inquiry
> mtx: Request Sense: Long Report=yes
> mtx: Request Sense: Valid Residual=no
> mtx: Request Sense: Error Code=70 (Current)
> mtx: Request Sense: Sense Key=Illegal Request
> mtx: Request Sense: FileMark=no
> mtx: Request Sense: EOM=no
> mtx: Request Sense: ILI=no
> mtx: Request Sense: Additional Sense Code = 25
> mtx: Request Sense: Additional Sense Qualifier = 00
> mtx: Request Sense: BPV=no
> mtx: Request Sense: Error in CDB=no
> mtx: Request Sense: SKSV=no
> INQUIRY Command Failed
> 
> # mtx -f /dev/sg1 inquiry
> mtx: Request Sense: Long Report=yes
> mtx: Request Sense: Valid Residual=no
> mtx: Request Sense: Error Code=70 (Current)
> mtx: Request Sense: Sense Key=Illegal Request
> mtx: Request Sense: FileMark=no
> mtx: Request Sense: EOM=no
> mtx: Request Sense: ILI=no
> mtx: Request Sense: Additional Sense Code = 25
> mtx: Request Sense: Additional Sense Qualifier = 00
> mtx: Request Sense: BPV=no
> mtx: Request Sense: Error in CDB=no
> mtx: Request Sense: SKSV=no
> INQUIRY Command Failed
> 
> On the other server:
> 
> tape drive (/dev/st0 not even present).
> 
> Can someone please help?
> 
> Thanks,
> 
> - xinhuan
> 
Some observations and some questions:

1) You would probably do better asking for this kind of help on a more
tape-centric or even Quantum specific forum.

2) If I read your description correctly, you have one tape changer with two
physical drives.  You can partition the library but there is still only one
changer.  That could be the problem.

3) You don't say how you attach the library to the servers.  I'm guessing fibre
channel through a FC switch.  Is this correct?  With the correct software both
servers could end up seeing the library as their own this way.

4) You can try doing a "rmmod sg" followed by a "modprobe sg".  This will result
in your systems resensing the SCSI bus.

Cheers,
Dave