Linux has software nice and ionice.

/bin/nice (or /usr/bin/nice)

these can be used to run some script or command / process with lower or higher priority regarding CPU and Disk I/O.

It means that other processes will have higher priority and our script will cause less negative impact on server performance (will run longer time probably).

(man nice)

Example use (give script lowest priority):
A) /bin/nice -n 19 /path/to/
B) nice -n 19 /path/to/

-n (range from -20 to 19, default is 10)
-n 19 is lowest priority
-n -20 highest process priority

(man ionice)

Example use (give script lowest disk priority):
A) /usr/bin/ionice -c2 -n7 /path/to/
B) ionice -c2 -n7 /path/to/

-n value is 0 - 7 (0 - highest priority, 7 lowest priority)
-c2 is best effort priority, -c1 is realtime highest process priority

NOTE: ionice may not work on OpenVZ VPS (virtual private servers)


/bin/nice -n 19 /usr/bin/ionice -c2 -n7 /path/to/
(runs the with lowest priority)