Mysql wont start after rsync /var/lib/mysql/* from old to new server

[Patricio Medina]

Hello, I have been following the steps described in

https://forum.froxlor.org/index.php?/topic/13952-teil-migration-howto AND

https://forum.froxlor.org/index.php?/topic/14391-froxlor-migration-auf-neuen-server-systemupgrade

to migrate a froxlor server from Debian 8 to Ubuntu Focal

Both servers were configured and running froxlor correctly.

Old server is running Mysql 7.4
New server is running Mysql 8

The problem is that after rsync var/lib/mysql/* from old to new, the mysql server in new is not starting.

The error showed is

mysql.service - MySQL Community Server
     Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
     Active: activating (start) since Mon 2021-02-22 13:22:51 UTC; 12s ago
    Process: 1173478 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
   Main PID: 1173487 (mysqld)
     Status: "Data Dictionary upgrade from MySQL 5.7 in progress"
      Tasks: 2 (limit: 38476)
     Memory: 234.8M
     CGroup: /system.slice/mysql.service
             └─1173487 /usr/sbin/mysqld
 

I have been searching for info but couldnt find it.

Please if someone have experienced this can share how it was solved.

Thank you

 

 

 

[d00p]

Well the status tells you pretty clearly:  Status: "Data Dictionary upgrade from MySQL 5.7 in progress"

[Patricio Medina]

Hello d00p, thanks for your reply. I thought the same as you but it has run for 4 days and still shows the same error.

Do you have any idea on what I can check?

Thank you.

[d00p]

So you've rsynced /var/lib/mysql/* completely from the old server to the new one?

[Patricio Medina]

That's right. I rsynced /var/lib/mysql/ on old to var/lib/mysql on new. Both locations are correct for mysql.

As you wrote in an old post, I stopped mysql server on new before rsyncing. 

The only thing I havent tried yet is to stop mysql on old AND new.

Any idea? Thank you

[d00p]

you should sync /var/lib/mysql directly only if mysql is not running as it might write/alter files while syncing

[Patricio Medina]

Ok, thank you. Yes, thats my next step. I will be doing it tonight. I will post the results here tomorrow anyway.

Thank you

[d00p]

Also, 5.7 to 8.0 might not be painless, try googling "upgrade mysql 5.7 to 8.0" or similar, to get help/info like https://mysqlserverteam.com/inplace-upgrade-from-mysql-5-7-to-mysql-8-0/