Output of iotop -oa:
Total DISK READ: 11.36 K/s | Total DISK WRITE: 117.42 K/s
TID PRIO USER DISK READ DISK WRITE SWAPIN IO> COMMAND
2628 be/4 mysql 37.47 M 92.05 M 0.00 % 1.05 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
2224 be/4 mysql 1508.00 K 608.00 K 0.00 % 0.23 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
10391 be/4 mysql 2.91 M 612.00 K 0.00 % 0.17 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
1326 be/4 root 0.00 B 40.78 M 0.00 % 0.11 % [kjournald]
11168 be/4 mysql 1352.00 K 488.00 K 0.00 % 0.11 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
16385 be/4 postfix 4.00 K 10.52 M 0.00 % 0.10 % cleanup -z -t unix -u
9571 be/4 mysql 764.00 K 224.00 K 0.00 % 0.07 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
2946 be/4 mysql 364.00 K 1912.00 K 0.00 % 0.04 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
10255 be/4 apache 24.00 K 16.00 K 0.00 % 0.04 % httpd
18452 be/4 mysql 976.00 K 628.00 K 0.00 % 0.05 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
18288 be/4 postfix 0.00 B 20.95 M 0.00 % 0.04 % cleanup -z -t unix -u
17366 be/4 postfix 0.00 B 8.91 M 0.00 % 0.03 % cleanup -z -t unix -u
14362 be/4 apache 20.00 K 28.00 K 0.00 % 0.02 % httpd
19423 be/4 mysql 788.00 K 204.00 K 0.00 % 0.06 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
13133 be/4 mysql 376.00 K 168.00 K 0.00 % 0.02 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
18282 be/4 postfix 0.00 B 20.44 M 0.00 % 0.02 % cleanup -z -t unix -u
11682 be/4 mysql 864.00 K 220.00 K 0.00 % 0.02 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
23830 be/4 apache 8.00 K 16.00 K 0.00 % 0.01 % httpd
19709 be/4 vmail 304.00 K 0.00 B 0.00 % 0.05 % dovecot/pop3
20070 be/4 mysql 272.00 K 140.00 K 0.00 % 0.12 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
20015 be/4 vmail 3.04 M 0.00 B 0.00 % 0.10 % dovecot/pop3
19990 be/4 postfix 2.39 M 28.00 K 0.00 % 0.08 % smtp -n smtp-amavis -t unix -u -c -o smtp_data_done_timeout=1200 -o smtp_send_xforward_command=yes -o disable_dns_lookups=yes -o max_use=20
19512 be/4 postfix 0.00 B 10.51 M 0.00 % 0.02 % cleanup -z -t unix -u
17885 be/4 apache 272.00 K 24.00 K 0.00 % 0.01 % httpd
15767 be/4 mysql 16.00 K 172.00 K 0.00 % 0.01 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
2151 be/4 root 0.00 B 0.00 B 0.00 % 0.01 % [flush-202:0]
2622 be/4 mysql 372.00 K 0.00 B 0.00 % 0.00 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
29510 be/4 mysql 4.00 K 112.00 K 0.00 % 0.00 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
20016 be/4 mysql 60.00 K 36.00 K 0.00 % 0.03 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
19706 be/4 vmail 380.00 K 4.00 K 0.00 % 0.01 % dovecot/imap
18298 be/4 clam 1488.00 K 0.00 B 0.00 % 0.00 % clamd
19908 be/4 postfix 0.00 B 4.08 M 0.00 % 0.02 % cleanup -z -t unix -u
17630 be/4 root 28.00 K 0.00 B 0.00 % 0.00 % -bash
20440 be/4 apache 132.00 K 16.00 K 0.00 % 0.00 % httpd
20000 be/4 vmail 8.00 K 0.00 B 0.00 % 0.01 % dovecot/imap
6261 be/4 postfix 336.00 K 0.00 B 0.00 % 0.00 % qmgr -l -t fifo -u
2055 be/4 mysql 28.00 K 0.00 B 0.00 % 0.00 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
2621 be/4 mysql 0.00 B 596.00 K 0.00 % 0.00 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
27499 be/4 vmail 136.00 K 8.00 K 0.00 % 0.00 % dovecot/imap
32465 be/4 mysql 36.00 K 0.00 B 0.00 % 0.00 % mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/~=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
18009 be/4 vmail 8.00 K 0.00 B 0.00 % 0.00 % dovecot/imap
5943 be/4 vmail 4.00 K 12.00 K 0.00 % 0.00 % dovecot/imap
20099 be/4 amavis 80.00 K 0.00 B 0.00 % 0.01 % amavisd (ch11-20099-11)
6754 be/4 postfix 8.00 K 0.00 B 0.00 % 0.00 % proxymap -t unix -u
20339 be/4 postfix 28.00 K 0.00 B 0.00 % 0.03 % smtp -n smtp-amavis -t unix -u -c -o smtp_data_done_timeout=1200 -o smtp_send_xforward_command=yes -o disable_dns_lookups=yes -o max_use=20
19757 be/4 vmail 8.00 K 0.00 B 0.00 % 0.00 % dovecot/imap
17889 be/4 apache 52.00 K 8.00 K 0.00 % 0.00 % httpd
17904 be/4 apache 20.00 K 20.00 K 0.00 % 0.00 % httpd
22902 be/4 apache 28.00 K 40.00 K 0.00 % 0.00 % httpd
17469 be/4 root 32.00 K 0.00 B 0.00 % 0.00 % python /usr/bin/iotop -oa
22900 be/4 apache 60.00 K 20.00 K 0.00 % 0.00 % httpd
14364 be/4 apache 16.00 K 12.00 K 0.00 % 0.00 % httpd
9106 be/4 vmail 4.00 K 0.00 B 0.00 % 0.00 % dovecot/imap
14363 be/4 apache 8.00 K 4.00 K 0.00 % 0.00 % httpd
17881 be/4 apache 44.00 K 12.00 K 0.00 % 0.00 % httpd
17888 be/4 apache 116.00 K 24.00 K 0.00 % 0.00 % httpd
23348 be/4 apache 4.00 K 16.00 K 0.00 % 0.00 % httpd
5958 be/4 vmail 4.00 K 0.00 B 0.00 % 0.00 % dovecot/imap