Storage size requirements for backup and replica

[peppeniello]

Hi all

I've read some posts about this topic and I've found this formula :

Backup size = C * (F*Data + R*D*Data)
Replica size = Data + C*R*D*Data
where
Data = sum of processed VMs size (actually used, not provisioned)
C = average compression/dedupe ratio (depends on too many factors, compression and dedupe can be very high, but we use 50% - worst case)
F = number of full backups in retention policy (1, unless backup mode with periodic fulls is used)
R = number of rollbacks (or increments) according to retention policy
D = average amount of VM disk changes between cycles in percent

and that RPS tool at https://rps.dewin.me/ is no longer supported in favour of Veeam Capacity Calulator (VCC) at https://calculator.veeam.com/vbr/
About VCC is the section Primary backup policy reffered to policy applied to short-term retention policy or to Long Term Retention Policy ? I'm confused about it

There are settings that I can use to estimate Replica Size using VCC ?

Thanks a lot

[HannesK]

Hello,
and welcome to the forums.

Primary backup policy is the backup job. That includes short-term and long-term. The tool expects, that synthetic full is used. With XFS / REFS that synthetic full is space-less anyway.



How could we make it clearer than having the "I" icon? As you mention rollbacks... removing "Reverse Incremental" backup would be nice, but too many people are still using it. So that's not really an option from a software perspective.

Best regards,
Hannes

PS: VCC is already "pre-defined" with "Veeam Cloud Connect"

[peppeniello]

HI

thanks a lot for reply.
About how to make clearer the tool settings I think that inside the pop your explanation :"Primary backup policy includes short-term and long-term, configured through GFS Points. The tool expects, that synthetic full is used and with XFS / REFS this synthetic full is space-less" could be useful even if for someone it's a redundancy.

About VCC. Well, I told that I'm confused