Some Forever Forward questions

[pshute]

About a year ago, I set up a daily job backing up one server as a test. I ticked the "Incremental" option and set it to retain 14 restore points. That's what's called Forever Forward? Compression was set to Optimal. I left this running daily for a year.

Question 1:
I was under the impression this would result in one vbk file and 13 vib files, with the vbk file having the oldest date. But the vbk is the youngest? Why?

Question 2:

The vbk file with yesterday's date is 39GB in size.

Today I ran some active fulls of this job to test different levels of compression. These are 30GB (Optimal), 26GB (High) and 24GB (Extreme). Why is the Optimal active full's vbk file so much smaller than the vbk file created by the Forever Forward? Has a year of injecting daily incrementals into the original active full done this?

[veremin]

I was under the impression this would result in one vbk file and 13 vib files, with the vbk file having the oldest date. But the vbk is the youngest? Why?

Unexpected, unless reverse incremental mode is selected.

Has a year of injecting daily incrementals into the original active full done this?

Correct.

[pshute]

Unexpected, unless reverse incremental mode is selected.

My mistake. I was looking at the modification dates of the files, rather than the dates in the file names. Of course the vbk file has the most recent modification date, because it has the oldest incrememental injected into it every day, but the dates in the filenames do show it correctly as the oldest restore point.

Has a year of injecting daily incrementals into the original active full done this?
Correct.

Why does that happen? I thought the process of injecting the oldest incremental should make it identical to a fresh full backup. How big can they get?