root@ubuntu1604:/data/php# cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=16.04
DISTRIB_CODENAME=xenial
DISTRIB_DESCRIPTION="Ubuntu 16.04.2 LTS"
root@ubuntu1604:/data/php# mysql --version
mysql Ver 14.14 Distrib 5.7.19, for Linux (x86_64) using EditLine wrapper
root@ubuntu1604:/data/php#

各位大虾，本人ubuntu小白。以前多用centos，设置/etc/mysql/mysql.conf.d/mysqld.cnf 中datadir= /data/mysql 就报错启动不了 改回datadir= /var/lib/mysql 就没事，十分奇怪。我说下我操作步骤：
1、在mysql启动时候拷贝 /var/lib/mysql到/data/mysql
2、给/data/mysql添加mysql权限
3、修改/etc/mysql/mysql.conf.d/mysqld.cnf里面的datadir= /data/mysql
4、修改/etc/apparmor.d/usr.sbin.mysqld里面的/var/lib/mysql r,和/var/lib/mysql/** rwk,
5、修改/etc/apparmor.d/abstractions/mysql里面的/var/lib字样
启动就不行 2L 贴报错日志

Aug 10 16:22:49 ubuntu1604 systemd[1]: Failed to start MySQL Community Server.
Aug 10 16:22:49 ubuntu1604 systemd[1]: mysql.service: Unit entered failed state.
Aug 10 16:22:49 ubuntu1604 systemd[1]: mysql.service: Failed with result 'exit-code'.
Aug 10 16:22:49 ubuntu1604 systemd[1]: mysql.service: Service hold-off time over, scheduling restart.
Aug 10 16:22:49 ubuntu1604 systemd[1]: Stopped MySQL Community Server.
Aug 10 16:22:49 ubuntu1604 systemd[1]: Starting MySQL Community Server...
Aug 10 16:22:50 ubuntu1604 kernel: [798505.549500] audit: type=1400 audit(1502353370.003:520): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/1031/status" pid=1031 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=123 ouid=123
Aug 10 16:22:50 ubuntu1604 kernel: [798505.549564] audit: type=1400 audit(1502353370.003:521): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=1031 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=123 ouid=0
Aug 10 16:22:50 ubuntu1604 kernel: [798505.549657] audit: type=1400 audit(1502353370.003:522): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/1031/status" pid=1031 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=123 ouid=123
Aug 10 16:22:50 ubuntu1604 kernel: [798505.685494] audit: type=1400 audit(1502353370.139:523): apparmor="DENIED" operation="mknod" profile="/usr/sbin/mysqld" name="/data/mysql/ubuntu1604.lower-test" pid=1031 comm="mysqld" requested_mask="c" denied_mask="c" fsuid=123 ouid=123
Aug 10 16:22:50 ubuntu1604 kernel: [798505.686650] audit: type=1400 audit(1502353370.139:524): apparmor="DENIED" operation="mknod" profile="/usr/sbin/mysqld" name="/data/mysql/ubuntu1604.lower-test" pid=1031 comm="mysqld" requested_mask="c" denied_mask="c" fsuid=123 ouid=123
Aug 10 16:22:50 ubuntu1604 kernel: [798505.686661] audit: type=1400 audit(1502353370.139:525): apparmor="DENIED" operation="mknod" profile="/usr/sbin/mysqld" name="/data/mysql/ubuntu1604.lower-test" pid=1031 comm="mysqld" requested_mask="c" denied_mask="c" fsuid=123 ouid=123
Aug 10 16:22:50 ubuntu1604 kernel: [798505.704181] audit: type=1400 audit(1502353370.155:526): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/data/mysql/ibdata1" pid=1031 comm="mysqld" requested_mask="wr" denied_mask="wr" fsuid=123 ouid=123
Aug 10 16:22:50 ubuntu1604 systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE
Aug 10 16:23:20 ubuntu1604 systemd[1]: Failed to start MySQL Community Server.
Aug 10 16:23:20 ubuntu1604 systemd[1]: mysql.service: Unit entered failed state.
Aug 10 16:23:20 ubuntu1604 systemd[1]: mysql.service: Failed with result 'exit-code'.
Aug 10 16:23:20 ubuntu1604 systemd[1]: mysql.service: Service hold-off time over, scheduling restart.
Aug 10 16:23:20 ubuntu1604 systemd[1]: Stopped MySQL Community Server.
Aug 10 16:23:20 ubuntu1604 systemd[1]: Starting MySQL Community Server...
Aug 10 16:23:20 ubuntu1604 kernel: [798536.114558] audit: type=1400 audit(1502353400.495:527): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/1121/status" pid=1121 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=123 ouid=123
Aug 10 16:23:20 ubuntu1604 kernel: [798536.114576] audit: type=1400 audit(1502353400.495:528): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=1121 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=123 ouid=0
Aug 10 16:23:20 ubuntu1604 kernel: [798536.114604] audit: type=1400 audit(1502353400.495:529): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/1121/status" pid=1121 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=123 ouid=123
Aug 10 16:23:20 ubuntu1604 kernel: [798536.249560] audit: type=1400 audit(1502353400.631:530): apparmor="DENIED" operation="mknod" profile="/usr/sbin/mysqld" name="/data/mysql/ubuntu1604.lower-test" pid=1121 comm="mysqld" requested_mask="c" denied_mask="c" fsuid=123 ouid=123
Aug 10 16:23:20 ubuntu1604 kernel: [798536.250734] audit: type=1400 audit(1502353400.631:531): apparmor="DENIED" operation="mknod" profile="/usr/sbin/mysqld" name="/data/mysql/ubuntu1604.lower-test" pid=1121 comm="mysqld" requested_mask="c" denied_mask="c" fsuid=123 ouid=123
Aug 10 16:23:20 ubuntu1604 kernel: [798536.250745] audit: type=1400 audit(1502353400.631:532): apparmor="DENIED" operation="mknod" profile="/usr/sbin/mysqld" name="/data/mysql/ubuntu1604.lower-test" pid=1121 comm="mysqld" requested_mask="c" denied_mask="c" fsuid=123 ouid=123
Aug 10 16:23:20 ubuntu1604 kernel: [798536.268258] audit: type=1400 audit(1502353400.647:533): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/data/mysql/ibdata1" pid=1121 comm="mysqld" requested_mask="wr" denied_mask="wr" fsuid=123 ouid=123
Aug 10 16:23:21 ubuntu1604 systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE
Aug 10 16:23:30 ubuntu1604 systemd[1]: Stopped MySQL Community Server.
Aug 10 16:23:30 ubuntu1604 systemd[1]: mysql.service: Unit entered failed state.
Aug 10 16:23:30 ubuntu1604 systemd[1]: mysql.service: Failed with result 'exit-code'.
Aug 10 16:23:30 ubuntu1604 systemd[1]: Starting MySQL Community Server...
Aug 10 16:23:30 ubuntu1604 kernel: [798546.171403] audit: type=1400 audit(1502353410.527:534): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/1187/status" pid=1187 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=123 ouid=123
Aug 10 16:23:30 ubuntu1604 kernel: [798546.171443] audit: type=1400 audit(1502353410.527:535): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=1187 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=123 ouid=0
Aug 10 16:23:30 ubuntu1604 kernel: [798546.171496] audit: type=1400 audit(1502353410.527:536): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/1187/status" pid=1187 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=123 ouid=123
Aug 10 16:23:31 ubuntu1604 systemd[1]: Started MySQL Community Server.

你要的答案
https://blogs.oracle.com/jsmyth/apparmor-and-mysql

查了半天，发现自己路径少了个/ 郁闷 谢谢 您给的文章看了 跟我写的步骤差不多 多谢

问题解决了 谢谢各位大大 楼主可以结贴了

没看明白，也是一直没有成功

您哪里出的问题 把你配置的步骤 和报错信息写出来看看