Can someone clarify a little bit what has been stated in TR-4003 re SnapInfo sizing please?
There is a useful hint on p.46: “Note that the size of a TLOG backup equals the used portion of the TLOG and not the actual TLOG file size. The used portion’s size may be determined by using the command DBCC SQLPERF(‘LOGSPACE’).”
Further down sizing SnapInfo sizing steps are explained, referring to a script in the Load Generation Scripts section of the Appendixes – but there is only a load generation script, useless for obtaining TLOG file size.
I googled a bit & found this script, which in my view does the job: