We have ~9TB MySQL database which consists from a few tables which are partitioned by day. Sum of daily information is ~20GB. Database is practically write only. There are at most tens of queries against the data per day.
InnoDB Barracuda type is used because of compressed data. MySQL version 5.5.12
What I would like to achieve is to use fast disks for current day partitions while there is data load activity. And somehow move those partitions to slow and cheap disks when day changes and new partition is started.
How can I do that with minimal or no downtime? Data load activity is 24/7 but can be delayed for a few minutes.