Changing the DataDir before or after configuring the Cluster?

MySQL & MariaDB Percona XtraDB Cluster 5.x
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(educational purposes)

Hey comm,

actually i’m just trying to understand the working of xtraDB Cluster and how to set it up proberly. In this situation i want to use 3 cloud servers, where each has a ssd volume connected.

Cause the SSD of the server itself is very small, i want to have the data directory of the xtraDB Cluster on these SSD volumes which are connected to the server, because i can upsize them when there is a need of it (up to 10 TB).

I already done the installation on the 3 servers as follows:

Now i would come up to configure nodes for write-set replication:

And i’m asking myself, if i should change the DataDir to the SSD volume before i do this or when is the best time for it.

Someone can give me a recommendation? Maybe a doc link, cause i didnt find something about changing the dataDir?

Best regards
Keon

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Hello @Keon,
MySQL’s data directory is set via config file /etc/my.cnf (or /etc/mysql/my.cnf depending on your OS). Look for [mysqld] section, and datadir= Shut down MySQL. Change this parameter to a new value. Copy the contents of /var/lib/mysql (the default) to this new location, ensure permissions/ownerships are correct, and then start MySQL.
Alternatively, you could have simply mounted your block device as /var/lib/mysql and not needed to change any mysql settings.