How to calculate the required data transfer rate for your network(s)
For backups over a network, you must move data from your client(s) to your media server(s) fast enough to finish backups within your backup window. Table: Network data transfer rates shows the typical transfer rates of some common network technologies. To calculate the required data transfer rate, use this formula:
Required network data transfer rate = (amount of data to back up) / (backup window)
Table: Network data transfer rates
Theoretical gigabytes per hour
Typical gigabytes per hour
Additional information is available on the importance of matching network bandwidth to your tape drives.
See Network and SCSI/FC bus bandwidth
The following is an example of how to calculate the required data transfer rate for your network(s).
This example makes the following assumptions:
Solution 1: Network Technology = 100BaseT (switched)
Typical transfer rate = 25 gigabytes per hour
A single 100BaseT network has a transfer rate of 25 gigabytes per hour. This network cannot handle your required data transfer rate of 62.5 gigabytes per hour.
In this case, you would have to explore other options, such as the following:
Backing up your data over a faster network (1000BaseT)
Backing up large servers to dedicated tape drives (SAN media servers)
Backing up over SAN connections by means of SAN Client
Performing off-host backups using Snapshot Client to present a snapshot directly to a media server
Performing your backups during a longer time window
Performing your backups over faster dedicated networks
Solution 2: Network Technology = 1000BaseT (switched)
Typical transfer rate = 250 gigabytes per hour
Based on Table: Network data transfer rates, a single 1000BaseT network has a transfer rate of 250 gigabytes per hour. This network technology can handle your backups with room to spare.
Calculate the data transfer rates for your networks to help you identify your potential bottlenecks. Several solutions for dealing with multiple networks and bottlenecks are available.
See Tuning suggestions for the NetBackup data transfer path
See Designing your backup system
See How to calculate the size of your NetBackup image database