what are the formula to calculate maximum size of total disk size for network backup to disk and i80 Quantum tapes

[martinlee2015]

would like to do a planning.

what are the formulas to calculate maximum size of total disk size for network backup to disk and i80 Quantum tapes in daily backup

input parameter : network link speed GB/min, network card speed GB/min, maximum 16 hours from 5:00 p.m. to next day 9:00 a.m., 

it first backup to disk in DR site and then DR site backup to tapes of i80 which has only one head drive which means only can run one backup tape job each time

[Colin_Weaver]

Sorry you are asking how long is a piece of string

Those sorts of statistics relate to the environmetal performance and to a certain extent the types of data being backed up. So there is no formula as it would be unique for every installation and even vary from day to day due to other things happening in the same enviromment and restricting the available performance in different ways. Even two different servers in one environment could backup data at different speeds. File sizes affect performance too - 1,000,000x 1mb files will backup slower than 10x 100,000mb files.

To add to this problems with a tape carttidge can mean one tape is slower than another (retries on tape writes etc)

The only way to work this out is to test it in your environment and monitor the results over more than one day.