Innodb; multiple data directories

Question

I have a requirement to store two Innodb database files on separate partitions. (one database on raid0 for speed, the other on raid1 for stability)

From what I\'ve r

Answer 1

I just wrote a blog post on this today: http://www.mysqlperformanceblog.com/2010/12/25/spreading-ibd-files-across-multiple-disks-the-optimization-that-isnt/

You don't want to do the symlinking thing - and InnoDB does not support DATA DIRECTORY/INDEX DIRECTORY.

You actually need stability of the data system wide for InnoDB. Let's say -

• You have critical tables A,B,C.
• Non-critical tables are D,E,F.
• If you relocated D,E,F to /mnt/RAID0, and you lost this volume, InnoDB will actually not allow you to access tables A,B,C any more either.
• Unless it can access all your data, InnoDB will refuse to start.

If you have two very different data requirements, you need two installs of MySQL ;)