Quantum DIGITALUNIX4 User Manual

DLT™1/7 TAPE UNIT INSTALLATION

Digital Unix 4.0;

IBM RISC System/6000 must have the appropriate SCSI interface for DLT drive to attached to, i.e., a SCSI
single-ended DLT drive can be attached only to a SCSI single-ended interface. The same is true for SCS I
differential attachment. After the DLT tape peripheral has been attached, you will need to perform certain
system operations that allow the DLT tape peripheral to be recognized.

Adding device definitions

Adding device definitions

Digital UNIX version 4.0 uses Dynamic Device Recognition to simplify adding support for
a new SCSI device. Adding a new device is a three-step process:

1. Use the ed, vi, or jot editor to add or modify a tape drive definition in the
/etc/ddr.dbase file. This file contains sections for each device definition. Adding a
new device definition is usually as easy as copying and pasting information from a
similar device and making one or two modifications.

2. Make the new definition(s) known to the system by issuing the command ddr_config

c /etc/ddr.dbase.

3. (optional) Generate the device files by running /dev/MAKEDEV for the added device.

When these steps are complete, your system is ready to use the new tape drive. You do not
need to reboot. If the new tape drive does not operate as you expect, you can repeat the
above steps to modify the definition until the device operates correctly.

Procedure for modifying the device definitions

Note: The device definitions in this document are for Digital UNIX version

4.0a. Later versions may contain slightly different default entries in the
/etc/ddr.dbase file.

Follow these steps to add a new tape drive to the /etc/ddr.dbase file:

Important: Always create a backup copy of the file before you modify it.

4. Login with root privileges.

5. Go to the /etc directory:

6. cd /etc

7. Make a backup copy of the original ddr.dbase file:

8. cp /etc/ddr.dbase /etc/ddr.dbase.orig

9. Edit the ddr.dbase file to add the new tape drive. See the following sections for the
required modifications for each type of Exabyte tape drive.

10. vi ddr.dbase

11. Save the changes to the file:

12. :w!

13. Go to the /dev directory:

14. cd /dev

15. Create device files for the new tape drive:

16. MAKEDEV [id]

Where [id] is the SCSI ID of the new tape drive. For example, MAKEDEV tz5 creates device
files for a tape drive at SCSI ID 5.

Assuming that no device files were previously created for any tape drives, the MAKEDEV
command creates the following eight device files in the /dev directory:

/dev/rmt0l Low density rewinding device
/dev/rmt0h High density rewinding device
/dev/rmt0m Medium density rewinding device
/dev/rmt0a Alternate density rewinding device
/dev/nrmt0l Low density non-rewinding device
/dev/nrmt0h High density non-rewinding device
/dev/nrmt0m Medium density non-rewinding device
/dev/nrmt0a Alternate density non-rewinding device

Your system is now ready to use the new tape drive.
You need to create device files for each tape drive only once. If you add more than one tape
drive, the next time you run MAKEDEV, it will create /dev/[n]rmt1[lhma], then
/dev/[n]rmt2[lhma], and so on for the additional tape drives.

Modifications for DLT1 tape drives

# ####################################################################
#
# TAPES:
#
# ####################################################################
#
# The "default" tape entry is as follows:
#
# PARAMETERS:
# TypeSubClass = rdat
# BlockSize = 0
# MaxTransferSize = 0xFFFFFF # 16MB-1 tape default