dmesg

[   14.165321] type=1400 audit(1433380188.225:39): apparmor="DENIED" operation="mknod" profile="/usr/sbin/mysqld" name="/srv/mysql/au01.lower-test" pid=3066 comm="mysqld" requested_mask="c" denied_mask="c" fsuid=0 ouid=0
[   14.165365] type=1400 audit(1433380188.225:40): apparmor="DENIED" operation="mknod" profile="/usr/sbin/mysqld" name="/srv/mysql/au01.lower-test" pid=3066 comm="mysqld" requested_mask="c" denied_mask="c" fsuid=0 ouid=0
[   14.165399] type=1400 audit(1433380188.225:41): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/etc/mtab" pid=3066 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=0 ouid=0
[   14.165850] type=1400 audit(1433380188.225:42): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/srv/mysql/au01-bin.index" pid=3066 comm="mysqld" requested_mask="rwc" denied_mask="rwc" fsuid=106 ouid=106

mysqld

# vim:syntax=apparmor
# Last Modified: Tue Jun 19 17:37:30 2007
#include <tunables/global>

/usr/sbin/mysqld {
  #include <abstractions/base>
  #include <abstractions/nameservice>
  #include <abstractions/user-tmp>
  #include <abstractions/mysql>
  #include <abstractions/winbind>

  capability dac_override,
  capability sys_resource,
  capability setgid,
  capability setuid,

  network tcp,

  /etc/hosts.allow r,
  /etc/hosts.deny r,

  /etc/mysql/*.pem r,
  /etc/mysql/conf.d/ r,
  /etc/mysql/conf.d/* r,
  /etc/mysql/*.cnf r,
  /usr/lib/mysql/plugin/ r,
  /usr/lib/mysql/plugin/*.so* mr,
  /usr/sbin/mysqld mr,
  /usr/share/mysql/** r,
  /var/log/mysql.log rw,
  /var/log/mysql.err rw,
  /var/lib/mysql/ r,
  /var/lib/mysql/** rwk,
  /var/log/mysql/ r,
  /var/log/mysql/* rw,
  /var/run/mysqld/mysqld.pid w,
  /var/run/mysqld/mysqld.sock w,
  /run/mysqld/mysqld.pid w,
  /run/mysqld/mysqld.sock w,

  /sys/devices/system/cpu/ r,

  # Site-specific additions and overrides. See local/README for details.
  #include <local/usr.sbin.mysqld>
}