Step 4: Attach SCSI cable
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Caution To avoid damaging the server or autoloader, ensure that both are powered off while you attach the SCSI cable.
1Make sure you are connecting to a recommended SCSI bus type. See “Checking the SCSI connection” on page 9. Do not connect the autoloader to the same bus as a RAID controller. For optimum performance, we recommend that your HP StorageWorks DAT autoloader is installed on a dedicated SCSI bus. If it is not, do not connect it to the same bus as your disk drive.
2Perform a normal system shutdown and turn off the server and any connected peripherals.
3Attach the VHD connection on the SCSI cable to the server’s external SCSI connector and secure it by tightening the screws.
4Attach the HD connection on the SCSI cable to one of the SCSI connectors on the rear panel of the autoloader and secure it by tightening the screws.(See figure 6.)
5Connect the multimode terminator to the autoloader’s other SCSI connector and tighten the screws to secure it. The multimode terminator detects whether the host bus adapter is SE or LVD and automatically provides the appropriate termination.
Why does the autoloader need a terminator?
Terminators are essential, as they provide the correct voltages on the SCSI bus and prevent unwanted signal reflections from interfering with data transfers. The rule is:
There must be termination at both physical ends of the bus and only at the ends.
Normally the HBA forms one end of the SCSI bus and provides termination. You, therefore, need to ensure that the other end of the bus is terminated. If the autoloader is at the end of the SCSI bus, the terminator must be attached to the autoloader.
If you want to attach additional devices to the SCSI bus after the autoloader, you will need to remove the SCSI terminator and attach the next device to this SCSI connector. Make sure that you attach the terminator to the last device in the chain.
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