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Veritas NetBackup™ SAN Client and Fibre Transport Guide

Last Published: 2020-09-14

Product(s): NetBackup (8.3.0.1)

Creating tape drive pass-through device files

On media servers, NetBackup creates pass-through paths for tape drives automatically. However, you can create them manually.

NetBackup also uses the tape drive pass-through device files for SAN Client.

Use one of the following two procedures:

Create pass-through tape drive device files
See “To create pass-through tape drive device files”.
Create SAN client pass-through device files
See “To create SAN client legacy pass-through device files”.

To create pass-through tape drive device files

Determine the devices that are attached to the SCSI bus by using the HP-UX ioscan -f command, as follows:
```
ioscan -f
Class    I  H/W Path     Driver S/W State  H/W Type   Description
=================================================================
ext_bus  7  0/7/0/       c720   CLAIMED    INTERFACE  SCSI C896 Fast Wide LVD
target  10  0/7/0/1.0    tgt    CLAIMED    DEVICE
tape    65  0/7/0/1.0.0  stape  CLAIMED    DEVICE     QUANTUM SuperDLT1
target  11  0/7/0/1.1    tgt    CLAIMED    DEVICE
tape    66  0/7/0/1.1.0  stape  CLAIMED    DEVICE     QUANTUM SuperDLT1
target  12  0/7/0/1.2    tgt    CLAIMED    DEVICE
autoch  14  0/7/0/1.2.0  schgr  CLAIMED    DEVICE     ADIC Scalar 100
target  13  0/7/0/1.3    tgt    CLAIMED    DEVICE
autoch  19  0/7/0/1.3.0  schgr  CLAIMED    DEVICE     IBM ULT3583-TL
target  14  0/7/0/1.4    tgt    CLAIMED    DEVICE
tape    21  0/7/0/1.4.0  atdd   CLAIMED    DEVICE     IBM ULT3580-TD1
target  15  0/7/0/1.5    tgt    CLAIMED    DEVICE
tape    19  0/7/0/1.5.0  atdd   CLAIMED    DEVICE     IBM ULT3580-TD1
```
This example output shows the following:
- The robotic control for an ADIC Scalar 100 library is on a SCSI bus with an instance number of 7. The SCSI ID is 2, and the LUN is 0. The robotic control for an IBM ULT3583-TL library is on the same SCSI bus at SCSI ID 3 and LUN 0.
- The ADIC library contains two Quantum Super DLT drives. One has a SCSI ID of 0 and a LUN of 0. The other has a SCSI ID of 1 and a LUN of 0.
- The IBM library contains two IBM Ultrium LTO drives. One has a SCSI ID of 4 and a LUN of 0. The other has a SCSI ID of 5 and a LUN of 0.
  Use the IBM atdd driver when you configure IBM tape drives on HP-UX. Configure atdd and BEST device paths according to the IBM driver documentation. Do not configure atdd for robotic control of IBM robots. For the latest recommended atdd driver version from IBM, check the Veritas support Web site.
Create the pass-through device files for the tape drives, as follows:
```
cd /dev/sctl
/usr/sbin/mknod c7t0l0 c 203 0x070000
/usr/sbin/mknod c7t1l0 c 203 0x071000
/usr/sbin/mknod c7t4l0 c 203 0x074000
/usr/sbin/mknod c7t5l0 c 203 0x075000
```
When you use the HP-UX mknod command for tape drives, the target is the SCSI ID of the tape drive. It is not the SCSI ID of the robotic control.
The previous commands create the following pass-through device files.
```
/dev/sctl/c7t0l0
/dev/sctl/c7t1l0
/dev/sctl/c7t4l0
/dev/sctl/c7t5l0
```
Although the pass-through device files for tape drives are used during NetBackup operation, they are not used during NetBackup configuration. During NetBackup tape drive configuration, use the following device files to configure the tape drives.
```
/dev/rmt/c7t0d0BESTnb
/dev/rmt/c7t1d0BESTnb
/dev/rmt/c7t4d0BESTnb
/dev/rmt/c7t5d0BESTnb
```

To create SAN client legacy pass-through device files

Determine the devices that are attached to the SCSI bus by using the HP-UX ioscan -f command, as follows:
```
ioscan -f
Class    I  H/W Path                Driver    S/W State   H/W Type    Description
=================================================================================
ext_bus  9  0/3/1/0.1.22.255.0      fcd_vbus  CLAIMED     INTERFACE   FCP Device Interface
target   4  0/3/1/0.1.22.255.0.0    tgt       CLAIMED     DEVICE
tape     6  0/3/1/0.1.22.255.0.0.0  stape     CLAIMED     DEVICE      ARCHIVE Python
tape     7  0/3/1/0.1.22.255.0.0.1  stape     CLAIMED     DEVICE      ARCHIVE Python
```
This example output shows that the instance number of the Fibre Channel HBA is 9. It also shows that the target mode drivers on the Fibre Transport media server appear as ARCHIVE Python devices. One has a SCSI ID of 0 and a LUN of 0; the other has a SCSI ID of 0 and a LUN of 1.
From HP-UX 11i V3, agile device view is recommended and preferred. If the ioscan -f command does not list any ARCHIVE Python device, refer to the To create SAN client agile pass-through device files (HP-UX 11i V3 and later versions) section to use agile device addressing method.
Determine the character major number of the sctl driver by using the following command:
```
lsdev -d sctl
Character  Block  Driver  Class
203        -1     sctl    ctl
```
The output from this command shows that the character major number for the sctl driver is 203.
Create the pass-through device files, as follows:
```
cd /dev/sctl
/usr/sbin/mknod c9t0l0 c 203 0x090000
/usr/sbin/mknod c9t0l1 c 203 0x090100
```
The following describes the device file name:
- c9 defines the instance number of the interface card.
- t0 defines the SCSI ID (the target).
- l1 defines the LUN (the first character is the letter "l").

Verify that the device files were created, as follows:

# ls -l /dev/sctl
total 0
crw-r--r--   1 root       sys        203 0x090000 Nov  1 13:19 c9t0l0
crw-r--r--   1 root       sys        203 0x090100 Nov  1 13:19 c9t0l1

To create SAN client agile pass-through device files (HP-UX 11i V3 and later versions)

Determine the devices instance number, SCSI number and lun number by using the HP-UX ioscan -kCtape -P wwid command as follows:
```
bash-4.4# ioscan -kCtape -P wwid
Class     I  H/W Path  wwid
===============================
tape    133  64000/0xfa00/0xa0  SYMANTECFATPIPE 0.0     limbo.com
tape    142  64000/0xfa00/0xa9  SYMANTECFATPIPE 0.1     limbo.com
```
Only the devices with the SYMANTECFATPIPE keyword in the wwid field are the devices to look for. This example output shows that the instance number of the SAN client specific tapes are 133 and 142. Based on two numbers following the SYMANTECFATPIPE keyword, they also show that the SCSI number of device instance 142 is 0 and the lun number is 1. In the same way, the SCSI number of device instance 133 is 0 and the lun number is 0.
Create the pass-through device files in the /dev/sctl/ directory as follows:
```
#cd /dev/sctl
#mksf -d estape -P  -I 133 -v -r  /dev/sctl/c133t0l0
making /dev/sctl/c133t0l0 c 12 0x0000a0
#mksf -d estape -P  -I 142 -v -r  /dev/sctl/c142t0l1
making /dev/sctl/c142t0l1 c 12 0x0000a9
```
Option -I is used to specify the instance number. Instances number are listed with the ioscan command in step 1.
The last part of the command mksf is an absolute name of the pass-through device.
/dev/sctl/ is the path where the pass-through device files must exist.
c142 defines the instance number of the tape device. t0 defines the SCSI ID (the target). l1 defines the LUN (the first character is the letter "l").

Verify that the device files were created using the following command:

bash-4.4# ls -l /dev/sctl
total 0
crw-r-----   1 bin        sys         12 0x0000a0 Jun 29 12:33 c133t0l0
crw-r-----   1 bin        sys         12 0x0000a9 Jun 30 09:39 c142t0l1