*** is there i/o wait? (wa: cpu time spent waiting for i/o) ***
# vmstat -SM 1 10 procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 1 1 0 26202 214 1857 0 0 30 168 442 97 6 1 86 6 0 2 1 0 26202 214 1857 0 0 12 1424 11973 49038 4 1 90 5 0 0 1 0 26203 214 1857 0 0 12 1488 11803 49221 4 1 90 5 0 0 1 0 26203 214 1857 0 0 12 1384 10354 41779 3 1 91 5 0 0 1 0 26203 214 1857 0 0 16 1520 11935 48012 4 1 90 5 0 1 1 0 26202 214 1857 0 0 12 1396 10635 44548 4 1 91 5 0 0 1 0 26201 214 1857 0 0 12 2788 13849 53045 4 2 88 6 0 0 1 0 26202 214 1857 0 0 16 1468 14214 58107 5 1 89 5 0 0 1 0 26202 214 1857 0 0 12 1504 13806 56521 4 1 89 5 0 0 1 0 26202 214 1857 0 0 12 1420 11390 49139 4 1 90 5 0
*** what processes are in a state of being blocked? ***
# ps aux | grep D USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 906 0.4 0.0 0 0 ? D 21:24 0:22 [jbd2/dm-1-8] root 1876 0.0 0.0 0 0 ? D 21:24 0:00 [flush-253:1]
*** strace ***
strace -ff -s10000 -p process_id add the -eopen flag to above to see which files are being accessed / modified