Compaq Backup and Recovery for Microsoft SQL Server 6.x
The network operating system used on all servers in this section was Windows NT 4.0. The network
protocol selected was TCP/IP. Networking hardware included:
x
Compaq NetFlex-3 and Netelligent network interface cards.
x
Compaq Netelligent 10Base-T Repeater.
x
Compaq Netelligent 100Base-TX Repeater.
x
CAT 5 UTP cables (supports both 10 Mbs & 100 Mbs).
Both servers were cabled to the 10Base-T repeater for the 10 Mbit tests, then re-connected to the
100Base-T repeater for the 100 Mbit tests. The 100 Mbit technology chosen was 100Base-TX.
Compaq supports other 100 Mbit Ethernet technology such as 100VG-Any LAN, but this was not
tested. 100Base-TX supports full-duplex mode for bi-directional throughput up to 200 Mb/s.
However, since most of the data transfer done here is unidirectional (from source server to destination
server), benefits of full-duplex would be minimal and were not tested.
Here we show the performance characteristics of backing up a database residing on one server to
storage devices on another server, by transmitting a single data path across a 10Base-T network
segment. Using ARCserve and its RAID option, the backup was done to a single 15/30-GB DLT tape
drive as well as to an array of from 1 to 3 tape drives. SQL Server native dump was used to send data
to a disk array.
Chart 11 - Backup of One Server Across Single 10BaseT Segment
The results obtained here are somewhat predictable. Given that the maximum transfer rate of a DLT
tape drive (not counting compression) as well as a 10Base-T network are the same (1.25 MB/sec), one
would expect to saturate the network wire with just a single DLT at the destination end. Furthermore,
no increase in performance would be expected by striping multiple DLT's into a tape array using the
ARCserve RAID Option. This is exactly what is shown in Chart-11, where the network saturates at
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