HP DDS/DAT drives UNIX, Linux and OpenVMS configuration guide (DW049-90915, November 2009)

HP Evolution II DDS/DAT drives: UNIX, Linux and OpenVMS configuration guide 31
this; see the relevant man page for more information. If you use this approach, set stinit.def as
described in the next section, ”Configuring non-compression device files”.
Configuring non-compression device files
The following process allows the use of non-compression device files. HP recommends the use of
files with the mode identifier of “m” (such as /dev/nst0m). This sets the mode to non-compression,
and the blocksize to variable.
1. Install mt-st if not already installed. You can find this on the Linux installation CD/DVD.
2. If the stinit.def file is not on the system (usually found in /etc), you need to create and edit
it:
a. Find an example file at
/usr/share/doc/mt-st-<version>/stinit.def.examples or
/usr/share/doc/packages/mt-st/stinit.def.examples
.
b. Copy the file to /etc and rename it from stinit.def.examples to stinit.def.
c. Edit the DAT entry in stinit.def to change the manufacture and model details. You can
find these details by viewing the /proc/scsi/scsi file.
The example below shows how to edit the file for a DAT 72 drive:
# A compressing DAT (DDS-1-DC or DDS-[234])
manufacturer=HP model = "C7438A" {
can-bsr can-partitions auto-lock
mode1 blocksize=0 compression=1
mode2 blocksize=1024 compression=1
mode3 blocksize=0 compression=0
mode4 blocksize=1024 compression=0 }ns for different kinds of tape
d. After editing the file, execute stinit or reboot the system.
For more information on how to use stinit and stinit.def, see the man stinit page.
Detecting autoloader LUNs in Linux
SCSI devices such as tape drives have a SCSI ID number from 0 to 15, which is the drive's address
on the SCSI bus. In addition there are Logical Unit Numbers (LUNs) within each SCSI device. A
single tape drive (not an autoloader) will usually just have one LUN (LUN 0), to which all SCSI traffic
is sent.
HP DDS/DAT autoloaders are multi-LUN devices:
• LUN0 is used to control the tape device and is where commands such as
READ and WRITE are
sent.
• LUN1 is used to control the medium changer mechanism and is where commands such as
MOVE
MEDIUM
are sent.
To verify that Linux sees both LUNs, check the file
/proc/scsi/scsi.