Compaq N2400 - TaskSmart - 1 GB RAM Administration Manual page 265

A-4 Compaq TaskSmart N2400 Administration Guide
Other tape devices use High Voltage Differential (HVD) or Low Voltage
Differential (LVD) connections. Typical HVD or LVD tape devices include
the Compaq DLT TL891 MiniLibrary, the Compaq TL895 Library, and other
autochangers. To use these devices, an optional SCSI tape controller must be
used in PCI slot 4 in the server. The optional HVD or LVD controller has two
SCSI buses, each capable of supporting up to two DLT 7000 (35/70-GB)
devices, for a total of four tape drive devices.
Before purchasing a tape device, make sure that the backup software supports
it. Most backup software supports all types of backup devices, but you should
confirm your specific choice by consulting the software vendor website.
Vendors usually post a hardware compatibility guide for each version of the
backup software application.
Fibre-Channel Environments
If your company is already sharing tape libraries, or planning this approach,
you need to ascertain which of the following Fibre Channel environments is
being used:
Fibre-Channel Arbitrated Loop (FC-AL)
Switched Fibre Channel
Fibre Channel loop environments connect servers, such as the
TaskSmart N2400 appliance, to backup devices using a Fibre Channel hub and
a Fibre-Channel-to-SCSI bridge, called a Fibre Channel tape controller. The
Fibre Channel loop host bus adapter (HBA) controller is inserted into PCI
slot 4 in the server, and a fiber link connects the controller to the fiber hub.
Other servers can also be connected to the hub in the same way. A separate
fiber link connects the hub to the Fibre Channel tape controller. Finally, a
differential or SE SCSI cable connects the tape controller to the actual SCSI
tape device or devices.
Fibre Channel switched environments are similar to loop environments, except
that a different HBA controller is used in PCI slot 4, and a fibre switch
replaces the fibre hub used in the loop environments. Switched environments
can be made more reliable than loop environments.
As with the SCSI-connected environments, verify that your chosen backup
software vendor supports the specific hardware environment that you plan to
operate.