what purpose is the check scan option in tune2fs
doing some math on our systems, we have a reboot patch about every other month which counts as a "mount". the file system is checked every 38 mounts.
if my logic is correct, the file system will be checked at the 3 year mark an then again at the 6 year mark. At the 6 year mark we hope to have the system replaced.
If a system is 5 years old it likely has had 1 filesystem check and is due for one in a year ( which the system will likely not ever see )
We also have devices that get rebooted less than twice a year so they would be checked every 20 years
It appears that in a production environment it would run 1 time in the lifetime of the server.