问题
So MySQL won't restart/start after a server reboot. No configuration files have been edited / any changes made. I have the same problem as this question where apparmor is causing these log entries:
Sep 27 11:18:53 staging audit[2986]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/2986/status" pid=2986 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=112 ouid=112
Sep 27 11:18:53 staging audit[2986]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=2986 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=112 ouid=0
Sep 27 11:18:53 staging audit[2986]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/2986/status" pid=2986 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=112 ouid=112
When these execptions are added to /etc/apparmor.d/usr.sbin.mysqld
as :
# fix issue with mysql not restarting
/proc/*/status r,
/sys/devices/system/node/ r,
/sys/devices/system/node/node0/meminfo r,
# Allow network access
Then as root : service apparmor reload; service mysql restart;
The logs now only display:
Sep 27 11:25:10 staging systemd[1]: Failed to start MySQL Community Server.
-- Subject: Unit mysql.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mysql.service has failed.
--
-- The result is failed.
Sep 27 11:25:10 staging systemd[1]: mysql.service: Unit entered failed state.
Sep 27 11:25:10 staging systemd[1]: mysql.service: Failed with result 'exit-code'.
Sep 27 11:25:10 staging systemd[1]: mysql.service: Service hold-off time over, scheduling restart.
Sep 27 11:25:10 staging systemd[1]: Stopped MySQL Community Server.
-- Subject: Unit mysql.service has finished shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mysql.service has finished shutting down.
Sep 27 11:25:10 staging systemd[1]: Starting MySQL Community Server...
-- Subject: Unit mysql.service has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mysql.service has begun starting up.
Sep 27 11:25:11 staging systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE
I have not made any configuration changes so I don't really know where else to look. I was going to reinstall MySQL, however, I have data that I don't have backed up :( pls help
回答1:
have you tried this for ubuntu 16.04 and up
sudo systemctl start mysql
回答2:
So i've managed to get it working although i don't know how this worked, but i ran:
apt-get remove mysql*; apt-get install mysql-server mysql-client ;
the first time i was still unable to start mysql. And then i ran it again and mysql has started to work again. I also was able to remove the lines:
/proc/*/status r,
/sys/devices/system/node/ r,
/sys/devices/system/node/node0/meminfo r,
from /etc/apparmor.d/usr.sbin.mysqld and reloaded apparmor.
来源：https://stackoverflow.com/questions/46445545/mysql-wont-start-ubuntu-16-04-2-x64