Computer Associates BABWBR1151S38 Implementation Guide - Page 20

Data Transfer Requirements Device type AIT-3 DLT 7000 DLT 8000 Super DLT Mammoth-2 Ultrium (LTO) IBM 9890 IBM 3590E Approximate Transfer rate 2:1 Maximum Capacity (compressed (compressed data) data) 31.2 MB/seconds=112.3 GB/hour 260 GB 10.0 MB/seconds=36.0 GB/hour 70 GB 12.0 MB/seconds=43.2 GB/hour 80 GB 24.0 MB/seconds=86.4 GB/hour 220 GB 24.0 MB/seconds=86.4 GB/hour 160 GB 30.0 MB/seconds=108.0 GB/hour 200 GB 20.0 MB/seconds=72.0 GB/hour 40 GB 15.0 MB/seconds=54.0 GB/hour 60 GB Even though a single device may not be able to give the data transfer rate of 200 GB per hour set by our example, using multiple media devices should be able to achieve this aggregate transfer rate. For example, if you are using Ultrium tape drives, you need 2 tape drives to achieve 200 GB per hour, or 5 DLT 8000 drives to achieve the same throughput. Network Bandwidth Considerations Now you need to consider your network. More than any other factor, your available network bandwidth determines the amount of data that you can realistically transfer during a backup period. The following table compares the performance of different types of networks. As you can see, network performance can significantly impede large backup operations. Network Type 10Base-T Ethernet Theoretical Transfer Rate 10 mbps =1.25 MB/seconds Realistic Throughput 40-50% Realistic Transfer Rate* 500 KB/seconds=1.8 GB/hour 20 Implementation Guide