I have MySQL running on SSDs, SSDs that I'm about to run out of space on. My webhost overcharges for SSDs and the majority of the data in MySQL is "archived" data (i.e. data that isn't actively used). I have larger HDDs that can hold this data. As such, I want to be able to move specific InnoDB tables from the SSDs to the HDDs.
One solution I've thought about and researched is moving the individual .ibd files (I have innodb_file_per_table enabled) for the specific tables in question to the HDDs and then symlink. However, researching this, it looks like that is a bad idea for InnoDB.
I've also seen that since 5.6, MySQL supports the DATA DIRECTORY command:
To create a new InnoDB file-per-table tablespace in a specific location outside the MySQL data directory, use the DATA DIRECTORY = absolute_path_to_directory clause of the CREATE TABLE statement.
Plan the location in advance, because you cannot use the DATA DIRECTORY clause with the ALTER TABLE statement. The directory you specify could be on another storage device with particular performance or capacity characteristics, such as a fast SSD or a high-capacity HDD.
The problem is, it looks like this is only supported for new tables. I want to do it for existing tables. Any tips on how? I'm running Percona MySQL, if it helps.
Thanks!
UPDATE: Here is what I tried, but I'm getting a syntax error:
CREATE TABLE abc_2 LIKE abc ENGINE=InnoDB DATA DIRECTORY='/xxx/mysql/archive/'
Apparently CREATE ... LIKE ... DATA DIRECTORY ... is a combination that is not supported.
Do SHOW CREATE TABLE to get the current definition. Edit it to add DATA DIRECTORY and INDEX_DIRECTORY. Then use the edited text to create the new table.
Then INSERT INTO new_tbl SELECT * FROM real_tbl; and shuffle the names: RENAME TABLE real_tbl TO old_tbl, new_tbl TO real_tbl;.
Verify the results and finally DROP old_tbl;