Mysql doesn't start after moving var/lib/mysql

MGibbons

5/26/24, 9:22 AM

I'm running mysql 8 under Xubuntu 20.04. I needed more space for my database so I moved it using rsync. I then updated /etc/mysql/mysql.conf.d/mysqld.cnf to my new datadir. I then ran sudo systemctl start mysql which failed: mysql.service: Start request repeated too quickly.

My /var/log/mysql/mysql.log file shows:

/usr/sbin/mysqld (mysqld 8.0.33-0ubuntu0.22.04.2) starting as process 11483
2023-05-25T22:50:49.385036Z 0 [Warning] [MY-010091] [Server] Can't create test file /var/lib/mysql/mysqld_tmp_file_case_insensitive_test.lower-test
2023-05-25T22:50:49.385044Z 0 [Warning] [MY-010159] [Server] Setting lower_case_table_names=2 because file system for /var/lib/mysql/ is case insensitive
2023-05-25T22:50:49.390198Z 0 [Warning] [MY-010075] [Server] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: 97f6b237-fb4e-11ed-87f4-448500680687.
mysqld: File '/var/lib/mysql/auto.cnf' not found (OS errno 13 - Permission denied)
2023-05-25T22:50:49.390250Z 0 [ERROR] [MY-010183] [Server] Failed to create file(file: '/var/lib/mysql/auto.cnf', errno 13)
2023-05-25T22:50:49.390259Z 0 [ERROR] [MY-010076] [Server] Initialization of the server's UUID failed because it could not be read from the auto.cnf file. If this is a new server, the initialization failed because it was not possible to generate a new UUID.
2023-05-25T22:50:49.390288Z 0 [ERROR] [MY-010119] [Server] Aborting
2023-05-25T22:50:49.390659Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.33-0ubuntu0.22.04.2)  (Ubuntu).

The main error seems to be

Failed to create file(file: '/var/lib/mysql/auto.cnf', errno 13)

which is understandable as /var/lib/mysql doesn't exist any more. I've also checked that the new datadir has correct permissions

/media/500GB/var/lib$ ls -l
total 4
drwx---r-- 10 mysql mysql 4096 May 25 12:08 mysql

How can I create the auto.cnf file in the correct location?

401

0 + 2

server

mysql

apache2

pbhj

5/26/24, 10:42 AM

Have you checked that the mysql user has permission to access the mount, it's different to the permission for access to the directory/files. IIRC, `mount | grep 500GB` should show the necessary info. You might need to add mysql user to the users group and mount the drive with access for `users`, for example.

MGibbons

5/26/24, 5:47 PM

Through webmin, I checked "Allow Users to mount this filesystem". mount | grep 500GB /dev/sda1 on /media/500GB type ext4 (rw,relatime). Restarted mysql butgot same results as before

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