- Plesk for Linux
An error message related to MySQL service appears in one of these log files:
The error message might look as follows:
CONFIG_TEXT: ERROR: [pool example.com] cannot get uid for user 'root': Too many open files (24)
CONFIG_TEXT: Error: SQLSTATE[HY000]: General error: 23 Out of resources when opening file '/tmp/#***.MYD' (Errcode: 24 - Too many open files)
CONFIG_TEXT: [ERROR] /usr/sbin/mysqld: Can't open file: './usr_web587_1/etqvi_languages.frm' (errno: 24 - Too many open files)
CONFIG_TEXT: Failed to process database 'wordpress_f' from domain 'example.com': MySQL error 1018: Can't read dir of './wordpress_f/' (errno: 24 "Too many open files") executing query: SHOW TABLE STATUS FROM `wordpress_f`
CONFIG_TEXT: [ERROR] Error in accept: Too many open files
CONFIG_TEXT: DB query failed: SQLSTATE[HY000]: General error: 1016 Can't open file: './psa/misc.frm' (errno: 24), query was: select param, val from misc
MySQL service goes down periodically.
Plesk fails to load or operations with MySQL databases fail with one of the following error messages:
PLESK_INFO: ERROR: PleskDBException: Unable to connect to database: mysql_connect(): MySQL server has gone away (Error code: 2006) (Abstract.php:69)
PLESK_INFO: DB query failed: SQLSTATE[HY000]: General error: 23 Out of resources when opening file '/tmp/#sql_2ff_0.MAI' (Errcode: 24 "Too many open files"), query was: DESCRIBE `sessions`
A Plesk backup is created with the following warning:
CONFIG_TEXT: WARNING : (mysql object 'johndoe_opencart_e') Not all the data was backed up into /var/lib/psa/dumps/clients/johndoe/domains/example.com/databases/johndoe_opencart_e_1 successfully. mysqldump: Couldn't execute 'show table status like 'address'': Can't read dir of './johndoe_opencart_e/' (errno: 24 - Too many open files) (1018)
Plesk disk usage statistics might not be calculated.
The open files limit has been reached by the MySQL service. When MySQL fails to open required files, the process gets hanged and systemd fails to stop MySQL process.
Warning: Increasing the open file limits might affect the amount of used connections. In order to avoid instability, consider increasing it as well by following instructions from this KB article.
For systemd operating systems
Note: systemd operating systems listed below have MariaDB installed by default. If MariaDB has been replaced by MySQL, follow the resolution steps for MySQL.
- CentOS 8
- CentOS 7
- Debian 9
- Ubuntu 18.04
- Ubuntu 16.04
For Debian 8 with MySQL installed
For initV operating Systems
- CentOS 6
- Ubuntu 14.04