HBA

Overview

A host bus adapter (HBA), also known as host controller or host adapter, is a device that is used to connect storage devices to networks. HBAs connect Fibre Channels, Small Computer System Interfaces (SCSI- pronounced "skizzy"), and eSATA devices to networks through Ethernet, Universal Serial Bus (USB), Integrated Drive Electronics (IDE), and FireWire connections.

HBA cards come in single, dual, and quad port configurations. The single ports are less expensive than dual ports if used on PCI-Express interfaces. Quad ports are more expensive than dual ports, so try to use a dual port when possible.

Benefits

Host bus adapters come with extensive vendor support. If a driver is available, independent software vendors can integrate the host bus adapter with a particular storage area network. You have flexible options in integrating your hardware platform with your storage area network. This flexibility keeps prices down. Performance characteristics are more predictable and less affected by network performance if the HBA does not require reassembly packets.

How It Works

You need a host bus adapter to connect devices in your storage area network. Host bus adapters are also required to host virtual machines. The virtual machine should be configured for booting a storage area network and does not require a direct connection to the host bus adapter.

There are different kinds of host bus adapter. The Ethernet HBA uses iSCSI technology including hardware for implementing Transmission Control Protocol (TCP) Offload Engines.

Consolidation of these interfaces reduces port costs and hassle for expanding internal ports. You can use different types of host bus adapters in a network. Even if one fails, the other will be functional and the operations will continue. Host bus adapters also simplify storage management procedures by providing a common interface.

A SCSI Bus connects multiple SCSI-based devices in a chain. A host bus adapter bridges the computer and these SCSI devices. A host bus adapter is configured by the Basic Input/output System (BIOS), which has the ability to boot the system off a SCSI device. The system has a device driver with a unique numerical ID. A host bus adapter allows more than one SCSI to be connected simultaneously. Host bus adapters support speeds of up to 20 gigabits.

Infini Band, ATA, SAS, SATA, and eSATA are host bus adapters that support other architectures.