C Determining Linux and UNIX SCSI Parameters

For the Linux and UNIX platforms, if you do not know the Small Computer System Interface (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.

This appendix contains these sections:

Determining SCSI Device Parameters on Linux
Determining SCSI Device Parameters on Solaris

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

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 scsin. 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 logical unit number (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

Determining SCSI Device Parameters on Solaris

To determine the Small Computer System Interface (SCSI) device parameter information on Solaris, there are two major tasks required:

To identify the SCSI target ID and SCSI logical unit number (SCSI LUN) for each tape device, you must probe the SCSI bus of your system for attached tape devices using commands at the console in the Open Boot PROM. This task is described in "Probing SCSI Target ID and LUN for Media Devices From Solaris Open Boot PROM".

Note:
Accessing the Open Boot PROM requires shutting down and restarting the operating system.
To determine the SCSI bus name-instance for each tape device, you must install the Oracle Secure Backup Solaris device driver, and then view the devices that were recognized by the driver and associate them with the tape device information gathered in the first step.

Note:
Installing the Oracle Secure Backup device driver on Solaris is performed after loading Oracle Secure Backup with setup, as described in "Loading Oracle Secure Backup Software on Linux or UNIX Using setup Script", but prior to installing Oracle Secure Backup as described in "Installing Oracle Secure Backup on Linux or UNIX with installob".

This task is described in "Viewing SCSI Bus Name-Instance Parameter Values in Solaris".

Probing SCSI Target ID and LUN for Media Devices From Solaris Open Boot PROM

To view Small Computer System Interface (SCSI) target ID and SCSI logical unit number (SCSI LUN) parameters for a tape device from the Solaris Open Boot PROM:

Log into the media server as root.
Bring the host to run level 0. For example:
```
# init 0
```
The system shuts down and eventually the Open Boot PROM ok prompt is displayed on the console.
At the ok prompt, set the Open Boot auto-boot? variable to false. For example:
```
ok setenv auto-boot? false
auto-boot?     =    false
ok
```
At the ok prompt, run the Open Boot reset-all command. For example:
```
ok reset-all
```
The system resets and eventually returns to an ok prompt again.
At the ok prompt, run the Open Boot probe-scsi-all command to display the SCSI parameters for all tape devices attached to this host. For example:
```
ok probe-scsi-all
```
Find the information in the output that corresponds to your SCSI devices. For example, this excerpt from the output for dlsun1976 includes the following information for the tape library and tape drive:
```
/pci@1f,4000/scsi@3,1
Target 0
    Unit 0        Removable Tape        EXABYTE EXB-85058SQANXR1
Target 1
    Unit 0        Removable Device type 8      EXABYTE EXB-10e      1.8
```
The output can be interpreted as follows:
- The device tree path for the SCSI bus to which both tape devices are attached is /pci@1f,4000/scsi@3,1. Make a note of this value.
  
  Note:
  This value is not used directly in Oracle Secure Backup tape device configuration, but is needed when determining the SCSI bus name-instance parameter for each tape device, using the process in "Viewing SCSI Bus Name-Instance Parameter Values in Solaris".
- The value for Target is the target ID. For example, in this output the target ID of the tape drive is 0, and the target ID of the tape library is 1.
- The value for Unit is the SCSI logical unit number (SCSI LUN). For example, in this output the SCSI LUN of both tape devices is 0.
For this example, assign each tape device the Oracle Secure Backup logical unit number 0.

Record the discovered parameters and the assigned Oracle Secure Backup logical unit number for each tape device.
To restart the host into Solaris, enter the following commands at the ok prompt:
```
ok setenv auto-boot? true
ok reset-all 
```

Viewing SCSI Bus Name-Instance Parameter Values in Solaris

To determine the Small Computer System Interface (SCSI) bus name-instance parameter to use for each tape device in Oracle Secure Backup:

Log into your media server as root.
Change directory to the install subdirectory under the Oracle Secure Backup home. For example:
```
# cd /usr/local/oracle/backup/install
```

Run the installdriver script to install the Oracle Secure Backup driver. For example:

# installdriver
NOTE: /usr/local/oracle/backup/.drv.solaris64/ob copied to /usr/kernel/drv/ob
NOTE: /usr/local/oracle/backup/.drv.solaris64/ob.conf copied to /usr/kernel/drv/ob.conf
NOTE: /usr/local/oracle/backup/.drv.solaris64/ob64 copied to /usr/kernel/drv/sparcv9/ob 

NOTE: The Oracle Secure Backup device driver has been successfully installed.

Once installed, the Oracle Secure Backup driver is associated with the tape devices that it can control on this media server.

Run the following command to view tape devices associated with the Oracle Secure Backup driver:
```
# du -a /devices|grep ob|cut -f2 
/devices/pci@1f,4000/scsi@3,1/ob@0,0:glm1
/devices/pci@1f,4000/scsi@3,1/ob@1,0:glm1 
```
The output contains the needed tape device information.
Parse the output from Step 4 using information from the output of probing the SCSI bus in "Probing SCSI Target ID and LUN for Media Devices From Solaris Open Boot PROM". For example, consider the line of output that reads:
```
/devices/pci@1f,4000/scsi@3,1/ob@1,0:glm1 
```
- To identify the SCSI bus used for each tape device in the du output, match the device tree paths in the probe-scsi-all output to the device tree paths in the output from Step 4 for each tape device.
  
  For example, in this case the bus used for both tape devices is identified in the probe-scsi-all output as /pci@1f,4000/scsi@3,1, and in the du output as /devices/pci@1f,4000/scsi@3,1.
- The ob@ in the path from the du output indicates that the tape device is controlled by the Oracle Secure Backup driver.
- The two numbers (in this case, 1,0) following the ob@ are the SCSI target ID and SCSI logical unit number (SCSI LUN) for each tape device. For this example, the SCSI target ID is 1 and the SCSI LUN is 0. These values correspond to the Exabyte tape library on dlsun1976, as identified in "Probing SCSI Target ID and LUN for Media Devices From Solaris Open Boot PROM".
- The value following the colon (:) is the needed SCSI bus name-instance value for this tape device. For this example, the value is glm1.

For host dlsun1976, parsing both lines of output from Step 4 leads to the final SCSI parameters shown in Table C-2.

Table C-2 dlsun1976 Tape Device Summary

Device	Oracle Secure Backup LUN	SCSI Bus Name-Instance	SCSI Target ID	SCSI LUN
Exabyte library	0	glm1	1	0
Exabyte drive	0	glm1	0	0