Re: Not RAM but hard drive...
> How do I know how much RAM I really need? Can I go by the file
> sizes of the data and index files, or does the data need way more
> (or less) space in memory compared to the files?
You can get an estimate of the memory required by using the formula
(SizeofDatabase * NumberOfReplicas * 1.1 ) / NumberOfStorageNodes
For SizeOfDatabase you should be able to use the sum of the sizes of all data and index files on disk.
If you have many VARCHAR fields, then you will likely need a bit more memory than that, because this column type is actually treated as fixed-width by the NDB Cluster engine.
Jon Stephens
MySQL Documentation Team @ Oracle
MySQL Dev Zone
MySQL Server Documentation
Oracle