Parallel SCSI HPE Smart Array controllers, RAID controllers, and most on-board HBAs do not
support multiple LUNs. For current HBA compatibility information, see the BURA Data Agile
Compatibility Matrix at http://www.hpe.com/info/ebs.
called "LUN scanning."
If possible, put each tape drive on its own parallel SCSI bus. For optimum performance, each
LTO-4 tape drive must be on its own Ultra 320 SCSI bus. This will give you the best performance
and easiest installation.
If a tape drive must share a parallel SCSI bus with one or more other devices or the library has
multiple tape drives that must share a bus, follow these guidelines to plan your parallel SCSI
busses for the highest performance:
Do not put a tape drive on the same parallel SCSI bus as a disk drive because the system
and backup performance will be slow when data is written from the hard drive to tape or
from tape to the hard drive.
Do not put a tape drive on the same parallel SCSI bus as a disk array because the disk and
the tape drive performance will be affected, most RAID controllers do not support multiple
LUNs, and the data on the disk array could become corrupted.
Avoid putting an SE SCSI device on the same bus as a tape drive because the SE device
will slow the tape drive to SE speed and reduce the allowable cable length.
Default SCSI addresses
The HBA also has a SCSI address, which is typically 7.
Verify that each device on the bus has a unique SCSI address. If these pre-configured addresses
will not be unique on a bus, you will need to change the SCSI address of one or more of the tape
drives during the installation process.
MSL2024: For full-height tape drives the default SCSI address is 4. For half-height drives,
the default SCSI address for the bottom drive is 4 and the default SCSI address for the top
drive is 5 as shown in
Figure 14 MSL2024 parallel SCSI tape drive default SCSI addresses
1. Tape drive with SCSI address 4
2. Tape drive with SCSI address 5
MSL4048: For full-height tape drives the default SCSI address is 4. For half-height drives,
the default SCSI address for the bottom drive in each full-height drive bay is 4 and the default
SCSI address for the top drive is 5 as shown in
SCSI addresses" (page
Installing the tape library
The tape library requires an HBA that supports multiple LUNs, which is also
"MSL2024 parallel SCSI tape drive default SCSI addresses" (page
"MSL4048 parallel SCSI tape drive default