System Stats when I/O Might Be the Bottleneck: 1. iostat -x <delay> <repeats> shows the io for each device: Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util sdb 0.00 121.67 0.00 454.67 0.00 7696.00 33.85 0.06 0.12 0.00 0.12 0.04 1.97 sda 0.00 3.00 0.00 5.33 0.00 857.33 321.50 0.07 12.31 0.00 12.31 2.12 1.13 avg-cpu: %user %nice %system %iowait %steal %idle 3.58 0.00 0.69 0.08 0.00 95.65 2. Identify the process that produces the most IO: sudo iotop -oPa -d <delay> (show process and accumulatively) Total DISK READ : 0.00 B/s | Total DISK WRITE : 71.88 M/s Actual DISK READ: 0.00 B/s | Actual DISK WRITE: 78.41 M/s PID PRIO USER DISK READ DISK WRITE SWAPIN IO> COMMAND 6937 be/3 root 0.00 B 60.00 K 0.00 % 5.78 % [jbd2/sdb2-8] 875 be/3 root