I've seen several discussions regarding this topic. But I still don't get it.
From the docs:
The size of the data that needs to be backed up from a client computer. Application size is not always identical to the size reported by file or database management tools.
New data written on media by each backup job.
Size on Media:
Size of deduplicated data written on the media.
Consider the following real job:
Job 1 (deduped disk lib is the destination):
App Size: 33.4TB
Data Written: 24.93
Size on Media: 7.30
1st question: what is the total size occupied by this job in the dedup disk lib?
2nd question: is data written size, before dedup? Does it account for sw compression only? both?
3rd question: is size on media just the size of unique blocks for the job (disregarding the baseline?)?