It looks for database errors before write the backup to a file?
it looks for a certain type of error and not all potential database errors:
it perform calculations on the source file (page level) to check if what is written was correct before it was written.
it wont check for business rules like unique coloms in tables.
This only functions if my database as the torn_page_detection off and the checksum on, correct?
consider checksum an upgrade to torn page detection. the mechanics are different. torn page detection covers a different/smaller group of errors then checksum.
What about the option:
Veify backup when finished
This function is only executed after the option "Perform checksums before writing to media " is executed, correct?
correct. perform checksums is done before writing to the media. verify is done when all pages have been written.
out of my head the option performs a RESTORE VERIFYONLY