Controlling blkio usage(systemd)

Setting a blkio limit for a user #

1. using iotop

   sudo iotop -o
   

2. create 10GB file

   dd if=/dev/zero of=afile bs=1M count=10000
   

   copy this file to the /dev/null

   dd if=afile of=/dev/null
   

   check iotop

3. limit read bandwidth ot only one MB per second

   sudo systemctl set-property user-1001.slice BlockIOReadBandwidth="/dev/sda 1M"
   

4. do a daemon-reload

   sudo systemctl daemon-reload
   

5. check cgroup filesystem

   cat /sys/fs/cgroup/blkio/user.slice/user-1001.slice/blkio.throttle.read_bps_device
   8:0 1000000
   

   the “8:0” represents the jamor and minor numbers of the /dev/sda device:

   ls -l /dev/sda
   

Setting a blkio limit for a service #

sudo systemctl set-property apache2.service BlockIOReadBandwidth="/dev/sda 1M"

When you set this property on the command line, you had to surround the /dev/sda 1M part with a pair fo double quotes. When you set this in a service file, you do not surround the /dev/sda 1M within double quotes.

Links #

man systemd.resource-control