Hi Blazer,
since your script is for an database-Server i'ld work with DB2-Timestamps. It's easier than doing the Math with dates from the Shell or system.
At the start of your check-script write the current timestamp into a file:
db2 -x "values (current timestamp)" > some/file.out // Database-Connection required!
If you want to test your file_system_check.ksh,
then
START_TIME=$(cat some/file.out)
CHECK_TIME=$(db2 -x "values (current timestamp - $RUNTIME minutes)" )
if [[ $CHECK_TIME > $START_TIME ]]; then
mailx -s bla
mail@address.com ...
fi
Hth
nvk