nice and ionice

You can reduce the impact of a job by combining these two commands:

1. nice modify the cpu scheduling of a command. Nicenesses range from -20 (most favorable scheduling) to 19 (least favorable)

2. ionice modify the io scheduling class and priority of a command

options:

• -c The scheduling class

  • 1 for real time
  • 2 for best-effort
  • 3 for idle

• -n The scheduling class data. This defines the class data, if the class accepts an argument. For real time and best-effort, 0-7 is valid data

• -p Pass in a process pid to change an already running process. If this argument is not given, ionice will run the listed program with the given parameters

I have used the below command on my own servers and it works well:

/usr/bin/nice -n 19 /usr/bin/ionice -c2 -n7 /usr/local/bin/backup.sh

These articles may also be of help:

• reduce load of backup scripts
• set io scheduling