I have a backup script that: compress some files generate md5 copy the compressed file to another server. the other server finishes comparing MD5 (to find copy errors). Here it's the core script: nice -n 15 tar -czvf $BKP $PATH_BKP/*.* \ | xargs -I '{}' sh -c "test -f '{}' && md5sum '{}'" \ | tee $MD5 scp -l 80000 $BKP $SCP_BKP scp $MD5 $SCP_BKP This routine got CPU at 90% at gzip routine, slowing down the production server. I tried to add a nice -n 15 but server still hangs. I've already read 1 but the conversation didn't help me. What is the best approach to solve this issue ? I am open to new architectures/solutions :)