I suggest with nice/ionice: ionice -c 3 nice -n 19 grep -R -e 'TREX_PID=%u' -e 'Remote VS is empty !' / You can also check the whole drive: ionice -c 3 n

I suggest with nice/ionice: ionice -c 3 nice -n 19 grep -R -e 'TREX_PID=%u' -e 'Remote VS is empty !' / You can also check the whole drive: ionice -c 3 nice -n 19 grep -ab -e 'TREX_PID=%u' -e 'Remote VS is empty !' /dev/sda