Solution to mysql failure to start due to insufficient disk space in ubuntu

Preface

Recently, I added two fields to a table in the database. Later, it prompted something like insufficient disk space. Then the database was disconnected, and I couldn't connect to it after that. Later, after thinking about it, I finally solved the problem. This experience was really terrifying. This article records the solution to the problem of mysql being unable to start due to insufficient disk space.

Here’s how

Operating system: Ubuntu. Insufficient disk space causes MySQL to fail to start, which can cause the following problems:

root@iZ28z558vv0Z:/etc/mysql# mysql -u root -p
Enter password: 
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)
root@iZ28z558vv0Z:/b# service mysql start
start: Job failed to start
root@iZ28z558vv0Z:/var/lib# service mysqld start
mysqld: unrecognized service

Solution: Find the mysql configuration file my.cnf:

root@iZ28z558vv0Z:/etc/mysql# ls
conf.d debian.cnf debian-start my.cnf
root@iZ28z558vv0Z:/etc/mysql# vi my.cnf

The datadir item in the file shows /var/lib/mysql

[mysqld]
#
# * Basic Settings
#
user = mysql
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
port = 3306
basedir = /usr
datadir = /var/lib/mysql
tmpdir = /tmp
lc-messages-dir = /usr/share/mysql
skip-external-locking

Because the disk space is insufficient, we need to check the location where MySQL saves data, the usage of the disk space of datadir or tmpdir, and check the usage of the disk space of datadir:

root@iZ28z558vv0Z:/var# df /var
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/xvda1 41151808 39038392 0 100% /

It can be seen from the above that the disk space availability is obviously 0, which is why mysql cannot be started. The problem can be solved by deleting other files in the /var directory to free up disk space, and then restarting the mysql service.

Summarize

The above is the full content of this article. I hope that the content of this article can be of some help to your study or work. If you have any questions, you can leave a message to communicate.