This is kind of a common problem and may have several reasons. Sometimes when we simply want to restart the MySQL Server, we can get such an error:
\nERROR! MySQL server PID file could not be found!<\/p>\n
First of all, always check if the \/tmp partition is full. This can happen when MySQL can’t write to the \/tmp<\/strong> partition to create a lock file. Also, this may be because, somehow the \/tmp<\/strong> partition has been cleared and the MySQL server is looking for the PID file there. So easy-peasy just create a new pid file and restart the server. It can also help to check the status, sometimes it helps. For example sometimes you can get an error like this : Well, it’s kind of obvious, just remove the lock file and restart the server.<\/p>\n $ rm \/var\/lock\/subsys\/mysql<\/strong> If none of these help, and you’re getting an error like this: Then there might be a more complicated problem. Check the log file at \/var\/lib\/mysql\/mydomain.com.err<\/strong> This line tells us that we have a compatibility problem with some of our tables and mysql fails to start in safe mode.<\/p>\n Now let’s change the way mysql starts to work around this situtation.<\/p>\n $ { echo “mysql_enable=\\”YES\\””; echo “mysql_args=\\”–skip-grant-tables –skip-networking\\””; } >> \/etc\/init\/rc.conf<\/strong><\/p>\n Time to restart<\/p>\n $ \/etc\/init.d\/mysqld restart<\/strong><\/p>\n You should a get successfull restart. Now try and upgrade the server. If it says you have the latest version, still force it. It will check every database if it’s ok. After that, we can return things to normal, comment out the last line we’ve added to \/etc\/init\/rc.conf<\/strong><\/p>\n $ sed -i ‘\/mysql_args\/s\/^\/#\/’ \/etc\/init\/rc.conf<\/strong> Hope this helps.<\/p>\n","protected":false},"excerpt":{"rendered":" This is kind of a common problem and may have several reasons. Sometimes when we simply want to restart the MySQL Server, we can get such an error: ERROR! MySQL server PID file could not be found! First of all, always check if the \/tmp partition is full. This can happen when MySQL can’t write […]<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_uag_custom_page_level_css":"","footnotes":""},"categories":[363,364],"tags":[373,689],"yst_prominent_words":[682,605,688,684,675,683,665,680,677,673,681,674,679,686,685,337,687,678,676,672],"class_list":["post-643","post","type-post","status-publish","format-standard","hentry","category-databases","category-mysql-databases","tag-mysql","tag-pid"],"jetpack_featured_media_url":"","uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false},"uagb_author_info":{"display_name":"Mustafa Emre Ayd\u0131n","author_link":"https:\/\/www.veriteknik.net.tr\/en\/author\/eaydin\/"},"uagb_comment_info":0,"uagb_excerpt":"This is kind of a common problem and may have several reasons. Sometimes when we simply want to restart the MySQL Server, we can get such an error: ERROR! MySQL server PID file could not be found! First of all, always check if the \/tmp partition is full. This can happen when MySQL can’t write…","_links":{"self":[{"href":"https:\/\/www.veriteknik.net.tr\/en\/wp-json\/wp\/v2\/posts\/643","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.veriteknik.net.tr\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.veriteknik.net.tr\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.veriteknik.net.tr\/en\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.veriteknik.net.tr\/en\/wp-json\/wp\/v2\/comments?post=643"}],"version-history":[{"count":1,"href":"https:\/\/www.veriteknik.net.tr\/en\/wp-json\/wp\/v2\/posts\/643\/revisions"}],"predecessor-version":[{"id":4166,"href":"https:\/\/www.veriteknik.net.tr\/en\/wp-json\/wp\/v2\/posts\/643\/revisions\/4166"}],"wp:attachment":[{"href":"https:\/\/www.veriteknik.net.tr\/en\/wp-json\/wp\/v2\/media?parent=643"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.veriteknik.net.tr\/en\/wp-json\/wp\/v2\/categories?post=643"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.veriteknik.net.tr\/en\/wp-json\/wp\/v2\/tags?post=643"},{"taxonomy":"yst_prominent_words","embeddable":true,"href":"https:\/\/www.veriteknik.net.tr\/en\/wp-json\/wp\/v2\/yst_prominent_words?post=643"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n$ df -h<\/strong><\/p>\n
\n$ touch \/tmp\/mysql.sock<\/strong>
\n$ service mysqld restart<\/strong><\/p>\n
\n$ service mysqld status<\/strong>
\nERROR! MySQL is not running, but lock file (\/var\/lock\/subsys\/mysql) exists<\/strong><\/p>\n
\n$ service mysqld restart<\/strong><\/p>\n
\n$ service mysqld restart<\/strong>
\nERROR! MySQL server PID file could not be found!<\/strong>
\nStarting MySQL. ERROR! The server quit without updating PID file (\/var\/lib\/mysql\/mydomain.com.pid).<\/strong><\/p>\n
\n$ tail \/var\/lib\/mysql\/mydomain.com.err<\/strong>
\n120602 16:54:09 mysqld_safe mysqld from pid file \/var\/lib\/mysql\/mydomain.com.pid ended<\/strong><\/p>\n
\n$ mysql_upgrade<\/strong><\/p>\n
\n$ mysql_upgrade –force<\/strong><\/p>\n
\n$ service mysqld restart<\/strong><\/p>\n