MySQL Extremely High Disk Activity (Read Operations)

Posted by Jake Schoermer on Server Fault See other posts from Server Fault or by Jake Schoermer
Published on 2013-01-22T01:18:42Z Indexed on 2013/10/29 9:58 UTC
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I have 1GB Linode VPS with a standard LAMP stack. Apache is tuned fine but for some reason MySQL's disk usage is high. This is causing really slow site load times. RAM and CPU usage are fine.

Can anyone give me any pointers on tuning mysql's disk performance? I'm using InnoDB. iotop output is below.

    Total DISK READ: 38.50 M/s | Total DISK WRITE: 27.20 K/s
  TID  PRIO  USER    DISK READ>  DISK WRITE  SWAPIN      IO    COMMAND                                                                                                                                                                                                    
 9808 be/4 mysql      22.40 M/s    0.00 B/s  0.00 % 63.75 % mysqld
10045 be/4 mysql       2.06 M/s    0.00 B/s  0.00 % 26.65 % mysqld
 9987 be/4 mysql    1694.38 K/s    0.00 B/s  0.00 % 18.33 % mysqld
10015 be/4 mysql    1554.47 K/s    0.00 B/s  0.00 % 12.71 % mysqld
10019 be/4 mysql    1461.21 K/s    0.00 B/s  0.00 %  5.58 % mysqld
 9839 be/4 mysql    1383.48 K/s    0.00 B/s  0.00 % 25.69 % mysqld
10031 be/4 mysql    1243.58 K/s    0.00 B/s  0.00 %  5.68 % mysqld
10023 be/4 mysql    1057.04 K/s    0.00 B/s  0.00 %  2.02 % mysqld
10020 be/4 mysql    1025.95 K/s    0.00 B/s  0.00 %  7.05 % mysqld
10001 be/4 mysql     808.33 K/s  683.97 K/s  0.00 %  1.16 % mysqld
10025 be/4 mysql     746.15 K/s    0.00 B/s  0.00 %  3.28 % mysqld
10043 be/4 mysql     715.06 K/s    0.00 B/s  0.00 %  0.48 % mysqld
10044 be/4 mysql     672.31 K/s    0.00 B/s  0.00 %  5.25 % mysqld
10034 be/4 mysql     668.42 K/s 1989.73 K/s  0.00 %  5.31 % mysqld
 9985 be/4 mysql     450.80 K/s  124.36 K/s  0.00 %  8.83 % mysqld
 9989 be/4 mysql     357.53 K/s    0.00 B/s  0.00 %  5.21 % mysqld
10033 be/4 mysql     186.54 K/s    0.00 B/s  0.00 %  1.59 % mysqld
10021 be/4 mysql     155.45 K/s  435.25 K/s  0.00 %  1.23 % mysqld
10007 be/4 mysql     124.36 K/s    0.00 B/s  0.00 %  0.53 % mysqld
 9763 be/4 www-data   38.86 K/s    0.00 B/s  0.00 %  4.56 % apache2 -k start
10027 be/4 mysql      31.09 K/s    0.00 B/s  0.00 %  4.24 % mysqld
    1 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % init
    2 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [kthreadd]
    3 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [ksoftirqd/0]
    4 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [kworker/0:0]
    5 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [kworker/u:0]
    6 rt/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [migration/0]
    7 rt/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [migration/1]

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