Compaq ProLiant 1500 DDS-3 Enhancing DAT Reliability, Capacity, and Performanc
Compaq ProLiant 1500 Manual
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- Compaq ProLiant 1500 | DDS-3 Enhancing DAT Reliability, Capacity, and Performanc - Page 1
, due to low-cost media and backward read/write compatibility with existing DDS-1 and DDS-2 media. This brief discusses DDS-3 technology and the Compaq 12/24 gigabyte (GB) DAT Drive, which is designed with DDS-3 technology. Please direct comments regarding this communication to the ECG Technology - Compaq ProLiant 1500 | DDS-3 Enhancing DAT Reliability, Capacity, and Performanc - Page 2
This test is not a determination of product quality or correctness, nor does it ensure compliance with any federal, state or local requirements. Compaq is registered with the United States Patent and Trademark Office. Microsoft and Windows NT are trademarks and/or registered trademarks of Microsoft - Compaq ProLiant 1500 | DDS-3 Enhancing DAT Reliability, Capacity, and Performanc - Page 3
paper also explains why DDS-3 provides low total cost of ownership. Finally, this brief describes the Compaq 12/24 GB DAT Drive with DDS-3 format, including the backup software that it supports. BACKGROUND INFORMATION DAT technology was initially developed for consumer audio recording. DDS is a data - Compaq ProLiant 1500 | DDS-3 Enhancing DAT Reliability, Capacity, and Performanc - Page 4
DDS technology, the first of which was the 2/4 GB DAT Drive (DDS-1), followed by the 4/8 GB DAT Drive (DDS-2). With the advent of DDS-3 technology, Compaq developed the 12/24 GB DAT Drive, which has a capacity of 12 GB native (uncompressed) and 24 GB compressed. - Compaq ProLiant 1500 | DDS-3 Enhancing DAT Reliability, Capacity, and Performanc - Page 5
be compressed at a 2:1 ratio, while graphic files can be compressed at a 5:1 ratio. However, a file that is already compressed will not compress further for the servomechanism. A system with an "embedded" servo, as in the Compaq 2/4 GB DAT and 4/8 GB DAT drives, uses the automatic track following ( - Compaq ProLiant 1500 | DDS-3 Enhancing DAT Reliability, Capacity, and Performanc - Page 6
reading ATF information from tracks immediately left and right of the primary track it is reading, the head centers its position on the track. The Compaq 12/24 GB DAT Drive does not use embedded servo tracking with ATF. Instead, it uses a timed tracking scheme that frees the ATF areas for - Compaq ProLiant 1500 | DDS-3 Enhancing DAT Reliability, Capacity, and Performanc - Page 7
ECG036/1297 7(&+12/2*< %5,() (cont'd) ... Other ways DDS-3 technology increases track space are by compressing sub-code information into less space and by packing user data into fewer, larger blocks, thereby reducing total overhead for data blocks. As a result of the increased linear bit density, - Compaq ProLiant 1500 | DDS-3 Enhancing DAT Reliability, Capacity, and Performanc - Page 8
ECG036/1297 7(&+12/2*< %5,() (cont'd) ... DDS-3's read-after-write (RAW) capability also improves the data transfer rate. RAW refers to the ability of a DDS drive to read and verify data immediately after it has been written. This is possible because of the extra set of read and write heads that - Compaq ProLiant 1500 | DDS-3 Enhancing DAT Reliability, Capacity, and Performanc - Page 9
practical standpoint, if a tape were used for a weekly backup, it should last for two years. However, because DDS cassettes are so inexpensive, Compaq recommends replacing them sooner to ensure a reliable backup. Low Total Cost of Ownership DDS-3 tape drives offer low total cost of ownership in two - Compaq ProLiant 1500 | DDS-3 Enhancing DAT Reliability, Capacity, and Performanc - Page 10
GB DAT Drive. Figure 10: Compaq 12/24 GB DAT Drive being inserted into a ProLiant server. The 12/24 GB DAT Drive is designed with TapeAlert support. TapeAlert is a tape drive status monitoring and messaging utility that automatically detects media and drive problems that could have a negative impact - Compaq ProLiant 1500 | DDS-3 Enhancing DAT Reliability, Capacity, and Performanc - Page 11
ECG036/1297 7(&+12/2*< %5,() (cont'd) ... Seagate Software Seagate Backup Exec® for Microsoft Windows NT, Novell NetWare 3.x and IntranetWare 4.0 all support the Compaq 12/24 GB DAT Drive. The Seagate software complements the 12/24 GB DAT Drive with advanced industry features, such as: • - Compaq ProLiant 1500 | DDS-3 Enhancing DAT Reliability, Capacity, and Performanc - Page 12
one SMART-2 Array Controller, fourteen 4.3 GB ultra-wide SCSI drives Microsoft Windows NT 4.0 Cheyenne ARCserve 6.0 (Build 516) Compaq 12/24 GB DAT Version 2.86 512 MB of 1 MB files RAIT-0 Compression Ratio 1:1 2:1 4:1 RAIT Setup 1:1 1:1 1:1 Backup Speed (MB/min) 48.31 91.26 132.01 Restore Speed - Compaq ProLiant 1500 | DDS-3 Enhancing DAT Reliability, Capacity, and Performanc - Page 13
Array Controller, fourteen 4.3 GB ultra-wide SCSI drives Microsoft Windows NT 4.0 Seagate Backup Exec version 7.0 Rev. 554a Compaq 12/24 GB DAT Version 2.86 512 MB of 1 MB files RAIT-0 Results: Compression Ratio 1:1 2:1 4:1 RAIT Setup 1:1 1:1 1:1 Backup Speed (MB/min) 50.37 89.10 127.17 Restore - Compaq ProLiant 1500 | DDS-3 Enhancing DAT Reliability, Capacity, and Performanc - Page 14
Array Controller, fourteen 4.3 GB ultra-wide SCSI drives Novell IntranetWare SMP Seagate Backup Exec version 7.0 Rev. 554a Compaq 12/24 GB DAT Version 2.86 512 MB of 1 MB files RAIT-0 Results: Compression Ratio 1:1 2:1 4:1 RAIT Setup 1:1 1:1 1:1 Backup Speed (MB/min) 50.40 90.60 129.30 Restore
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C
ONTENTS
’’6²³´±(QKDQFLQJ±’$7±5HOLDELOLW\µ
&DSDFLW\µ±DQG±3HUIRUPDQFH
Mid-size businesses and branch offices using departmental servers with storage
requirements of 24 GB or less and running Microsoft Windows NT
®
, Novell
NetWare
®
3.x or IntranetWare
®
4.0 have a growing need for high performance, high
capacity, and reliable backup methods.
Digital Data Storage-3 (DDS-3) technology,
which is the recording format used by Digital Audio Tape (DAT) products, meets this
need with three times the capacity and twice the data transfer rate of DDS-2
technology and offers improved automated head cleaning mechanisms that enhance
backup reliability.
DDS-3 also provides low total cost of ownership for customers,
due to low-cost media and backward read/write compatibility with existing DDS-1
and DDS-2 media.
This brief discusses DDS-3 technology and the Compaq 12/24 gigabyte (GB) DAT
Drive, which is designed with DDS-3 technology.
Please direct comments regarding this communication to the ECG Technology Communications Group at this
Internet address: