Database server on SSD vs Database files on SSD


I have a bunch of jails with their databases running in the same jails. To increase the system responsiveness, i am planning to move the databases to SSD. I could either move the database server (create its own DB jail) or simply move the DB files to SSD (and use null mount).

Which is a better choice for system responsiveness?

Ideally both, or more ......

Placing the database files on the SSD definitely will improve performance.

The database application itself should largely remain in RAM, provided there is enough and there are not resources competing for it.

However, if you are short on RAM or too many other applications contending for it (causing lots of page faults), then moving the database server as well may help. In this case, the OS will be reading the executable off disk on demand.

If you are super short on RAM, placing swap on the SSD will help, because applications can get taken completely out of memory and dumped there.

Probably the best scenario is to have a single, separate, database server for all of the jails, but that may not be practical for various reasons.