Home / server / Questions / 456455
In Process
Bryan Agee
Asked: 2012-12-09 18:23:44 +0800 CST

Does it work to run mysql with the data directory on a CephFS mount?

  • 772

We have a database cluster that uses MySQL on DRBD with Pacemaker+Corosync, which is great. My question is whether it is possible (and whether anyone has been successful) to mount a CephFS drive to /var/lib/mysql and run MySQL from there.

The advantage would be that MySQL could then run on any cluster node, without the 2 node constraint of DRBD (or worse, the complexity of DRBD on DRBD).

mysql

3 Answers

  1. Yes, it will work but you can't run more then one mysql instance same time.

    Better just use mysql master-master replication WITHOUT drbd, put one failover ip(probably from 10.0.0.0 network) and use mysql_proxy project to put all write on one mysql(failover ip) and spread read to multiple. That will work excelent and will not have issues of mysql master-master setup becuase only one node do writes.

    • 2

  2. If its a solution for mysql cluster that you are looking for, you should take a look at galera, which offers an easy way of multi master replication. You should have at least three nodes though.

    • 2

  3. No. I wish you could. Unfortunately you can't have multiple mysql servers accessing the same data files. Mysql doesn't cope with it and you'll probably just get corrupted.

    You can however place the mysql data onto cephfs with a single mysql instance, that does work as does RBD.

    (yeah I know an old question, but I wanted to do this and found out that you can't. The answers were not entirely clear)

    • 1