Owner's manual

always has the tape drive at LUN 0 and the robot at LUN 1.
3. For each LUN that needs to be discovered by Linux, issue the following command:
echo "scsi-add-single-device H C I L">/proc/scsi/scsi
H C I L refers to the nexus described in step 2. So, with the Pow erVault 124T robot configured at LUN 1, type:
echo "scsi-add-single-device 3 0 0 1">/proc/scsi/scsi
The echo command will force a scan of each device at the given nexus.
4. Type cat /proc/scsi/scsi again to verify that all devices are now listed. The output will look similar to the following:
Attached devices:
Host: scsi3 Channel: 00 Id: 00 Lun: 00
Vendor: QUANTUM Model: ULTRIUM 4 Rev: xxxx
Type: Sequential-Access ANSI SCSI revision: 04
Attached devices:
Host: scsi3 Channel: 00 Id: 00 Lun: 01
Vendor: DELL Model: PV-124T Rev: Vxx
Type: Sequential-Access ANSI SCSI revision: 04
Administrators should add the echo command to the Linux boot scripts because the device information is not persistent and must be created each time the system
boots up. One example file that can be used for storing the commands is /etc/rc.local. Note that configuring additional devices on a server or a storage area network
(SAN) can cause the devices to be reordered, which requires administrators to modify the commands.
NOTE: This procedure must be run each time the server is booted. Also, if backup application services are running (for example, they automatically start when the OS
loads), they must be disabled and re-enabled after the above procedure.
The other way to enable LUN support is to recompile the kernel and enable LUN scanning in the controller driver, but it requires advanced know ledge of Linux and will not be
covered here. However, it will allow the server to always boot and see the device without any manual procedures.
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