MySQL fails to start when a Plesk server lacks disk space: SQLSTATE[HY000] No space left on device 500 Plesk\Exception\Database

Errors: ERROR: Plesk\Exception\Database
DB query failed: SQLSTATE[HY000]: General error: 1021 Disk full (/var/tmp/#sql_3b95_1); waiting for someone to free some space…, <…>

Server Error
500
Zend_Db_Adapter_Exception
SQLSTATE[HY000][2002] No such file or directory

Resolution
Connect to a Plesk server via SSH
Running following to delete temp files. replace the number with the for which you want to remove the logs
find /tmp -type f -mtime +10 -exec rm {} \;
# find /var/tmp -type f -mtime +10 -exec rm {} \;

Remove Plesk temporary files and backup files

# rm -rf /usr/local/psa/PMM/tmp/* /usr/local/psa/tmp/*

/usr/local/psa/admin/bin/pmm-ras –get-dump-list –type=server | grep ‘message’ | grep -v [0-9]_[0-9]
<message>backup_info_2010230005.xml: </message>
<message>backup_info_2010300005.xml: </message>

Restart the service once done
service psa restart