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NetBackup System Administrator’s Guide - Windows NT Server
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Transfer rate
Transfer rate depends on factors such as:
• Speed of the backup device. For example, sending backups to a tape having
a maximum transfer rate of 400 kilobytes per second normally takes less
time than to a tape that transfers at only 200 kilobytes per second (assuming
other factors allow taking advantage of the faster transfer rate).
• Available network bandwidth. The theoretical network bandwidth is about
10 megabits per second for Ethernet and 100 megabits per second for FDDI
and 100 base T. The available bandwidth, however, is less than this and
depends on how much other network traffic is present. For example,
multiple backups occurring on the same network compete for bandwidth.
• Speed with which the client can process the data. This varies with the
hardware platform and depends on the other applications running on the
platform. File size is also an important factor. Clients can process larger files
faster than smaller ones. You can back up 20 files that are 1 megabyte in
size, faster than 20,000 files that are 1 kilobyte in size.
• Speed with which the server can process the data. Like client speed, server
speed also varies with the hardware platform and depends on the other
applications running on the platform. The number of concurrent backups
being performed also affects server speed.
See the next topic “Determining NetBackup Transfer Rate” for ways to
compute the transfer rate for your clients.
Device delays
Device delays are due to factors such as the device being busy, loading the
media, and finding the place on the media at which to start writing the backup.
These delays depend on the devices and computing environments and can
vary widely.
Determining NetBackup Transfer Rate
You can calculate three different variations of the backup transfer rate by using
the data provided in NetBackup reports. The three rates and the methods for
calculating them are as follows.
NetBackup 3.2 System Administrator's Guide for Windows NT
NetBackup 3.2 System Administrator's Guide for Windows NT
