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User's Manual

ManualsBrandsQuantum ManualsStorageQuantum DAT 40 Drive
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Drive operation and maintenance
33
•
Place the drive in a position that provides stable temperatures. Do not place the
drive near open windows, fans, heaters or doors.
•
Do not read from or write to cartridges when a temperature change of 10
°
C per
hour is occurring.
Data Compression
Default operation for the DAT 72 and DDS-4 drives is to have data compression
enabled—the drive automatically compresses all data written to tape and
decompresses all compressed data read from tape.
The degree of compression varies with the type of data being processed.
Data with high degrees of redundancy, such as structured database files or graphics
files, can be compressed most efficiently, often at a ratio of 2:1 or more. Data with
little redundancy, such as executable programs, can be compressed the least.
The SCSI Mode Select command can switch the drive into compressed or
uncompressed mode for writing data regardless of the position of switch number 1
(see "Data compression (switches 1 and 2)" in Chapter 3). When reading, the drive
automatically selects compressed or uncompressed mode, depending on the data
that is read.
Loading Revised Firmware from Seagate Firmware Cartridges
Flash Memory
Another technological advancement incorporated into the DAT 72 and DDS-4 drives
is flash memory, which is useful if the drive’s SCSI firmware needs to be upgraded.
With the permanently installed, electrically upgradeable flash memory, revised SCSI
firmware for the drive can be loaded through:
1.
Seagate OEM firmware cartridges
2.
The host SCSI bus; or
3.
The drive serial port.
The flash memory feature enables qualified OEMs who need to revise DAT 72 and
DDS-4 drive SCSI firmware to do so quickly and easily. Flash memory also prolongs
the life cycle of a drive because many new techniques—such as increasing the
capacity of the drive through support for longer tapes—may require only a firmware
upgrade.
Firmware Download Process via Tape
To load a firmware upgrade tape, follow these steps.
1.
Power on the host system with the DAT 72 or DDS-4 drive installed.