mariadb won't start after upgrade

SUSE Linux Enterprise Server SLES Updates
1

Hi,
we have upgrade a SLES 12.1 to 12.5. After the update the installed mariadb won’t start.
The database wasn’t upgraded. So we started mariadb with “mysqld_safe”, did the upgarde of the tables,
but now we get the error message:

mysql-systemd-helper[28790]: chmod: changing permissions of '/usr/local/mysql/data': Read-only file system

The filesystem IS readable!
Also we can start the database using

/usr/lib/mysql/mysql-systemd-helper start

The everything is working and the DB can be accessed. However we do not understand why
“rcmysqld” restart or “service mysql restart” is not working.

How can we debug this problem ?
Any idea is well come!

Bye, Peer

2

OK - it seems the non standard location of the datadir caused the problem.
Changing

/usr/lib/systemd/system/mariadb.service
to
# Prevent writes to /usr, /boot, and /etc
ProtectSystem=none

# Prevent accessing /home, /root and /run/user
ProtectHome=false

fixed the problem. Now everything works well.

Bye