Accessing tape drive using passthrough driver

[Marco Senft]

I'm currently using a HP DAT24 tape drive which is working fine when 
using standard unix tools like mt, tar or dump. Here's the dmesg output 
concerning the tape drive:

ahc1: <Adaptec 2940 SCSI adapter> port 0xe000-0xe0ff mem 
0xd8020000-0xd8020fff irq 11 at device 11.0 on pci0
aic7870: Single Channel A, SCSI Id=7, 16/253 SCBs
sa0 at ahc1 bus 0 target 6 lun 0
sa0: <HP C1537A L105> Removable Sequential Access SCSI-2 device
sa0: 10.000MB/s transfers (10.000MHz, offset 15)

However, we recently bought a software called "TapeWare" (Version 7) 
which does not recognize the drive. The technical support of the 
manufacturer told me that I am "accessing the tape drive currently 
through ST but this is no way for Tapeware to access the drive." I 
should use the SG driver instead. This sounds like they're talking of 
Solaris stuff, and recommended me to "just look at your OS documentation 
on how to load up SG vs ST".

If I understand this correctly, these drivers are called "sa" and "pass" 
in the FreeBSD world. I'm using the GENERIC 4.7-RELEASE kernel 
currently, which is compiled with both the "sa" and the "pass" devices.

There are some "pass" devices under /dev:

 > ls -la /dev/pass*
crw-------  1 root  operator   31,   0 Oct 21  2002 pass0
crw-------  1 root  operator   31,   1 Oct 21  2002 pass1
crw-------  1 root  operator   31,   2 Oct 21  2002 pass2
crw-------  1 root  operator   31,   3 Oct 21  2002 pass3

I have four hard drives attached to the first controller, don't know if 
this has any influence on the list above.


So if someone just could tell me if and how I can make sure that the 
tape drive is accessible using the "pass" driver, I'd be really happy.


Cheers,
marco


-- 
Marco Senft
Technische Treuhand GmbH        http://www.t2g.ch/