IBM E16RMLL-I - Tivoli Storage Manager, Implementation Manual

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IBM Tivoli Storage Manager Implementation Guide
Workload calculations
An important consideration for designing the overall Tivoli Storage Manager
solution is the total amount of data that the Tivoli Storage Manager server will
need to support for backup or restore over a particular time frame.
A normal approach to estimate the network bandwidth needed is to consider all
client information backed up in the same backup window using the following
procedure:
1. Calculate the amount of data a Tivoli Storage Manager server will have to
accommodate during its nightly backup window and ensure that the hardware
can reasonably accommodate the data.
2. Calculate the amount of data that will be restored from a disaster recovery
Tivoli Storage Manager server and ensure that the hardware will meet DR
recovery SLAs.
We can calculate the workload for a Tivoli Storage Manager server in a
theoretical environment. As an example, the environment has the following
systems that we must back up:
򐂰 Twenty workstations
Each workstation has 60 GB of file data.
– Incremental forever backup with a change of approximately 10%
– Six-hour backup window
򐂰
Four database servers
Each server has 100 GB of database data.
– Full backups with a change of 100%
– Six-hour backup window
So doing the calculation for backup workload, each night we will need to back up:
(60 × 20 × .10)+ (100 × 4 ×1) = 520 GB
And dividing that by the time allowed for the backup:
So the network interfaces, drives, Tivoli Storage Manager server, and all other
infrastructures must handle this amount of data in order to meet SLAs for this
environment. Note that this type of calculation does not only apply to backups—it
can and should be done for disaster recovery restores and single system
restores.
Hr
GB
Hr
GB
6 . 86
6
520
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