What is the reason for the failure to start MySQL after the ubuntu server restarts?

it was fine before rebooting, but after rebooting, it will never be able to start again

root@iZuf6acp86oa3jizjzwaqdZ:~-sharp service mysql start
Job for mysql.service failed because the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details.
root@iZuf6acp86oa3jizjzwaqdZ:~-sharp systemctl status mysql.service
 mysql.service - MySQL Community Server
   Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
   Active: activating (start-post) (Result: exit-code) since Wed 2018-12-19 14:13:09 CST; 22s ago
  Process: 5124 ExecStart=/usr/sbin/mysqld (code=exited, status=1/FAILURE)
  Process: 5116 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
 Main PID: 5124 (code=exited, status=1/FAILURE);         : 5125 (mysql-systemd-s)
   CGroup: /system.slice/mysql.service
           control
             5125 /bin/bash /usr/share/mysql/mysql-systemd-start post
             5194 sleep 1

Dec 19 14:13:09 iZuf6acp86oa3jizjzwaqdZ systemd[1]: Starting MySQL Community Server...
Dec 19 14:13:11 iZuf6acp86oa3jizjzwaqdZ systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE

root@iZuf6acp86oa3jizjzwaqdZ:~-sharp journalctl -xe
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit mysql.service has begun starting up.
Dec 19 14:31:27 iZuf6acp86oa3jizjzwaqdZ audit[1938]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/1938/status" pid=1938 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=111
Dec 19 14:31:27 iZuf6acp86oa3jizjzwaqdZ kernel: audit: type=1400 audit(1545201087.234:39): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/1938/status" pid=1938 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=111
Dec 19 14:31:27 iZuf6acp86oa3jizjzwaqdZ audit[1938]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=1938 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=0
Dec 19 14:31:27 iZuf6acp86oa3jizjzwaqdZ audit[1938]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/1938/status" pid=1938 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=111
Dec 19 14:31:27 iZuf6acp86oa3jizjzwaqdZ kernel: audit: type=1400 audit(1545201087.238:40): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=1938 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=0
Dec 19 14:31:27 iZuf6acp86oa3jizjzwaqdZ kernel: audit: type=1400 audit(1545201087.238:41): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/1938/status" pid=1938 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=111
Dec 19 14:31:29 iZuf6acp86oa3jizjzwaqdZ systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE
Dec 19 14:31:58 iZuf6acp86oa3jizjzwaqdZ 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.
Dec 19 14:31:58 iZuf6acp86oa3jizjzwaqdZ systemd[1]: mysql.service: Unit entered failed state.
Dec 19 14:31:58 iZuf6acp86oa3jizjzwaqdZ systemd[1]: mysql.service: Failed with result "exit-code".
Dec 19 14:31:58 iZuf6acp86oa3jizjzwaqdZ systemd[1]: mysql.service: Service hold-off time over, scheduling restart.
Dec 19 14:31:58 iZuf6acp86oa3jizjzwaqdZ 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.
Dec 19 14:31:58 iZuf6acp86oa3jizjzwaqdZ 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.
Dec 19 14:31:58 iZuf6acp86oa3jizjzwaqdZ audit[2036]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/2036/status" pid=2036 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=111
Dec 19 14:31:58 iZuf6acp86oa3jizjzwaqdZ audit[2036]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=2036 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=0
Dec 19 14:31:58 iZuf6acp86oa3jizjzwaqdZ audit[2036]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/2036/status" pid=2036 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=111
Dec 19 14:31:58 iZuf6acp86oa3jizjzwaqdZ kernel: audit: type=1400 audit(1545201118.491:42): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/2036/status" pid=2036 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=111
Dec 19 14:31:58 iZuf6acp86oa3jizjzwaqdZ kernel: audit: type=1400 audit(1545201118.491:43): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=2036 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=0
Dec 19 14:31:58 iZuf6acp86oa3jizjzwaqdZ kernel: audit: type=1400 audit(1545201118.491:44): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/2036/status" pid=2036 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=111
Dec 19 14:32:00 iZuf6acp86oa3jizjzwaqdZ systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE
Dec 19 14:32:01 iZuf6acp86oa3jizjzwaqdZ CRON[2068]: pam_unix(cron:session): session opened for user root by (uid=0)
Dec 19 14:32:01 iZuf6acp86oa3jizjzwaqdZ CRON[2067]: pam_unix(cron:session): session opened for user root by (uid=0)
Dec 19 14:32:01 iZuf6acp86oa3jizjzwaqdZ CRON[2069]: (root) CMD (php /var/www/html/tiebasign/do.php)
Dec 19 14:32:01 iZuf6acp86oa3jizjzwaqdZ CRON[2071]: (root) CMD (php /var/www/html/tiebaid/test_only_cli_run_cw123456.php)
Dec 19 14:32:01 iZuf6acp86oa3jizjzwaqdZ cron[649]: Please install an MTA on this system if you want to use sendmail!
Dec 19 14:32:01 iZuf6acp86oa3jizjzwaqdZ CRON[2067]: (root) MAIL (mailed 378 bytes of output but got status 0x00ff from MTA
                                                    )
Dec 19 14:32:01 iZuf6acp86oa3jizjzwaqdZ CRON[2067]: pam_unix(cron:session): session closed for user root
Dec 19 14:32:01 iZuf6acp86oa3jizjzwaqdZ cron[649]: Please install an MTA on this system if you want to use sendmail!
Dec 19 14:32:01 iZuf6acp86oa3jizjzwaqdZ CRON[2068]: (root) MAIL (mailed 180 bytes of output but got status 0x00ff from MTA
                                                    )
Dec 19 14:32:01 iZuf6acp86oa3jizjzwaqdZ CRON[2068]: pam_unix(cron:session): session closed for user root
Dec 19 14:32:29 iZuf6acp86oa3jizjzwaqdZ 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.
Dec 19 14:32:29 iZuf6acp86oa3jizjzwaqdZ systemd[1]: mysql.service: Unit entered failed state.
Dec 19 14:32:29 iZuf6acp86oa3jizjzwaqdZ systemd[1]: mysql.service: Failed with result "exit-code".
Dec 19 14:32:29 iZuf6acp86oa3jizjzwaqdZ systemd[1]: mysql.service: Service hold-off time over, scheduling restart.
Dec 19 14:32:29 iZuf6acp86oa3jizjzwaqdZ 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.
Dec 19 14:32:29 iZuf6acp86oa3jizjzwaqdZ 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.
Dec 19 14:32:29 iZuf6acp86oa3jizjzwaqdZ audit[2141]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/2141/status" pid=2141 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=111
Dec 19 14:32:29 iZuf6acp86oa3jizjzwaqdZ kernel: audit: type=1400 audit(1545201149.732:45): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/2141/status" pid=2141 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=111
Dec 19 14:32:29 iZuf6acp86oa3jizjzwaqdZ audit[2141]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=2141 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=0
Dec 19 14:32:29 iZuf6acp86oa3jizjzwaqdZ kernel: audit: type=1400 audit(1545201149.736:46): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=2141 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=0
Dec 19 14:32:29 iZuf6acp86oa3jizjzwaqdZ audit[2141]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/2141/status" pid=2141 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=111
Dec 19 14:32:29 iZuf6acp86oa3jizjzwaqdZ kernel: audit: type=1400 audit(1545201149.740:47): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/2141/status" pid=2141 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=111 ouid=111
Dec 19 14:32:31 iZuf6acp86oa3jizjzwaqdZ systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE
lines 2166-2247/2247 (END)

Feb.25,2022

post a log, turkey!


start it in mysqld_safe mode and take a look at the error report


it seems that AppArmor is not configured properly, not SELinux.

you can refer to this article and add the missing permissions to
https://support.plesk.com/hc/.

.
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1beaaa8-31a01.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1beaaa8-31a01.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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