How do I measure the impact of subfile backup?

[purdon]

How do I measure the impact of subfile backup on backup storage for capacity planning?

Adding amount X to a file doesn't seem to result in a dfference in the number of bytes reported during backup, regardless of whether I am using subfile backup or not.

I don't seem see any specific type in the "backups" table for the system for which I have activated this - everything seems to be "FILE" or "DIR".

Can anyone help?

Thanks,
Jim