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# C Determining Linux SCSI Parameters

For the Linux and UNIX platforms, if you do not know the SCSI parameters of a tape device, then you must determine them before you begin installation. This appendix describes procedures for determining SCSI device parameters on Linux and UNIX.

## C.1 Determining SCSI Device Parameters on Linux

To obtain tape device information on Linux, use the `cat` command to view the contents of `/proc/scsi/scsi`. For example:

    # cat /proc/scsi/scsi

See Also:

"Identifying and Configuring Linux Attach Points" for information about configuring attach points for Linux

Example C-1 shows sample output for a host called `storabck05` with two attached tape devices.

Example C-1 Sample /proc/scsi/scsi Contents

    Attached devices:
    Host: scsi0 Channel: 00 Id: 02 Lun: 00
      Vendor: IBM      Model: ULTRIUM-TD2      Rev: 4772
      Type:   Sequential-Access                ANSI SCSI revision: 03
    Host: scsi0 Channel: 00 Id: 04 Lun: 00
      Vendor: ADIC     Model: Scalar 24        Rev: 237A
      Type:   Medium Changer                   ANSI SCSI revision: 02

A device of type `Sequential-Access`, such as the first tape device in the list, is a tape drive. A device of type `Medium Changer`, such as the second tape device, is a tape library.

For each tape device, the information needed is found in the line that reads:

    Host: scsi0 Channel: 00 Id: 02 Lun: 00

The output can be interpreted as follows:

- The host bus adapter number is the numeric part of the value `scsi` `n`. For example, for both tape devices in this output the host bus adapter number is `0`.

- The value for `Channel` is the SCSI bus address. For example, in this output the SCSI bus address is `0`.

- The value for `Id` is the target ID. For example, in this output the ID of the tape drive is `2`, and the ID of the tape library is `4`.

- The value for `Lun` is the SCSI LUN. For example, in this output the SCSI LUN of both tape devices is `0`.

By convention, the tape library and tape drive can each be assigned `0` as the Oracle Secure Backup logical unit number.

Based on the output shown in Example C-1, Table C-1 summarizes the tape device information for storabck05.

Table C-1 storabck05 Device Summary

Device | Host Bus Adapter | SCSI bus address | Target ID | SCSI LUN
--- | --- | --- | --- | ---
Library | 0 | 0 | 2 | 0
Tape drive | 0 | 0 | 4 | 0