DE

↑ ↓ select, Enter open, Esc close

Check all MySQL tables for errors

harmless rootMySQL and MariaDBdebian, ubuntu
root@server
mysqlcheck --all-databases --check --silent

Runs CHECK TABLE on every table of all databases. With --silent, only tables with errors or warnings are shown. Worthwhile after crashes, full disks or messages like “Table is marked as crashed”.

Note: The check creates load and may briefly lock MyISAM tables. mysqlcheck --repair can only repair MyISAM and Aria tables, not InnoDB.

Also searched as

  • mysql table corrupted
  • table is marked as crashed
  • check database for errors

Related one-liners

All in MySQL and MariaDB

Analyze the slow query log for the slowest queries

#mysqldumpslow -s t -t 10 /var/log/mysql/mariadb-slow.log
harmlessMySQL and MariaDB

Back up a single database consistently as gzip

$mysqldump --single-transaction --quick -u dbuser -p wp_example | gzip > /var/www/vhosts/example.com/wp_example.sql.gz
harmlessMySQL and MariaDB

Back up all databases into one gzipped file

#mysqldump --single-transaction --quick --all-databases --routines --events | gzip > /root/all-databases.sql.gz
harmlessMySQL and MariaDB

Back up each database into its own gzipped file

#for db in $(mysql -NBe 'SHOW DATABASES' | grep -Ev '^(information_schema|performance_schema|sys)$'); do mysqldump --single-transaction --quick "$db" | gzip > "/root/db-backup/$db.sql.gz"; done
harmlessMySQL and MariaDB

Compare max connections with the peak so far

#mysql -e "SHOW GLOBAL STATUS LIKE 'Max_used_connections'; SHOW GLOBAL VARIABLES LIKE 'max_connections';"
harmlessMySQL and MariaDB

Create a MySQL database with its own user

#mysql -e "CREATE DATABASE wp_example CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci; CREATE USER 'wp_example_user'@'localhost' IDENTIFIED BY 'SecurePassword'; GRANT ALL PRIVILEGES ON wp_example.* TO 'wp_example_user'@'localhost';"
cautionMySQL and MariaDB

Read first, then run.

The commands on myline.de act directly on servers, files and databases. A wrong path or placeholder can delete data irreversibly or make a server unreachable.

  • All commands are provided without warranty and are not tested on every system.
  • Understand what a command does before running it, and check every placeholder.
  • Make a backup first and, if possible, try it on a test system.
  • You run commands at your own risk. Liability for damages is excluded to the extent permitted by law.