Installation and Configuration | Black Box SCSI-2 LVD guide

CHAPTER 4: Installation and Configuration

CAUTION!

If any hard drive connected to the Adapter already has data stored on it, changing the head mapping will corrupt or erase that data and could cause other unexpected problems. If you want to keep the data on a drive, please back it up before changing the “DOS Space > 1GB” setting, then delete the target drive’s existing partitions with this Setup Utility’s “Format” Disk Utility function or the DOS FDISK utility. Then, after you change this setting, you can restore and reinstall from the backup.

All device drivers for the Adapter will support different head mappings based on the setting of this option:

Under MS-DOS, OS/2, and Windows NT, we recommend the “Yes” setting for any hard disk whose capacity is greater than 1 GB.

SCO UNIX does not have a 1-GB barrier, but it must know whether or not the boot-file system is located within the first 1024 cylinders of disk space in order to perform its kernel-boot routines. If your root file system is larger than 1 GB or is located beyond the first 1 GB of disk space, you should set "Dos Space > 1GB" to “Yes.” Otherwise, you can safely set it to “No” (although, to be on the safe side, we recommend that you set it to “Yes” anyway).

Note that, unlike the other operating systems the Adapter supports, SCO UNIX cannot support having drives with different head mappings attached to the same bus (channel). The head mapping used on the drive with SCSI ID 0 must be used on all other drives attached to the same bus.

On machines running multiple operating systems, you must use the same head mapping for any given hard drive across operating systems. Unless one of your oper- ating systems is SCO UNIX, however, different drives can have different head mappings.

In general, we recommend that, to be on the safe side, you set “DOS Space > 1GB” to “Yes” for any SCSI hard disk with capacity greater than 1GB.

Spin Up Disk Drive: Set this option to “Yes” to have the SCSI Host Adapter initiate motor spin-up for SCSI disk drives. This way, the Adapter’s BIOS can conserve system power during boot-up by signaling the attached devices to start at delayed intervals. The factory-default setting for this option is “No.” This option has no effect on peripherals that are not disk drives.

SCSI-2 LVD specifications

The Black Box SCSI-2 LVD (Low Voltage Differential) represents a significant advancement in data storage and connectivity technology, particularly in environments requiring high performance and reliability. As a variant of the SCSI (Small Computer System Interface) standard, it is optimized for faster data communication, essential for modern computing needs.

One of the main features of SCSI-2 LVD is its capability to handle increased data transfer speeds compared to its predecessors. It supports a maximum data transfer rate of up to 80 MB/s, which is double that of the original SCSI-2 single-ended signaling. This increase in speed is largely due to the differential signaling that LVD employs, allowing for reduced electromagnetic interference and extended cable lengths while maintaining signal integrity. The technology effectively converts the SCSI bus into a more robust system that can accommodate various devices without compromising performance.

The SCSI-2 LVD standard is backward compatible, meaning that it can interface with older SCSI devices, albeit at reduced speeds. This compatibility is significant for users looking to upgrade their systems without discarding existing hardware. This makes SCSI-2 LVD an attractive choice for enterprise environments where legacy systems are common.

Another key characteristic is the flexible cabling options provided by SCSI-2 LVD. It can support cable lengths of up to 12 meters, which is beneficial for large data center configurations where space between devices can be substantial. This extended range does not typically come at the expense of performance, ensuring that data integrity remains high, even over longer distances.

In terms of technology, LVD employs lower voltage levels, which not only contributes to greater power efficiency but also minimizes heat generation in devices. This is particularly crucial in data centers where temperature management can impact hardware longevity and reliability. The combination of lower voltage use and differential signaling makes SCSI-2 LVD well-suited for high-density environments.

Error correction and handshaking features are also integral to SCSI-2 LVD, enhancing its robustness against data loss during transmission. These characteristics make it a reliable choice for applications requiring consistent and high-speed data access, such as server arrays and high-performance computing tasks.

Overall, Black Box SCSI-2 LVD stands out due to its impressive speed, compatibility, and extensive cabling options, positioning it as a reliable solution for demanding data environments. It effectively bridges the gap between legacy systems and modern technology, ensuring that users can optimize their data handling capabilities without significant disruption.