Limit CPU consumption for processes

Compression algorithms eat CPU. While they are needed for backups you do not want to put your resurces down just because of one process. Use cpulimit for it then:

$ mycommand.sh & sleep $delay & cpulimit -e gzip -l 30 -z

Looking at the man pages you will realize we are limitting overall usage to 30% of the whole available CPU (if 3 processors then around 10% each) and the -z option will make cpulimit to quit if no gzip process is found, hence the delay for the command will depend on what that command actually does.