On Tue, Jul 5, 2011 at 8:49 PM, Les Mikesell lesmikesell@gmail.com wrote:
On 7/5/2011 1:30 PM, Rudi Ahlers wrote:
On Tue, Jul 5, 2011 at 8:20 PM, Les Mikeselllesmikesell@gmail.com
wrote:
How much can that matter? Reads are going to be cached in main RAM anyway - which is pretty cheap these days.
Yes, but I suppose it all depends on the needs of the server in question
:)
In our case, with web servers, reads (i.e. opening websites, downloading content) far outweighs writes (which are basically logs, file uploads, and sessions being written to disk.
In case of forums (we have many clients with forums) reads& writes are sometimes equal, but even then reads are still more common in our case than writes.
But it doesn't matter if you lose the read cache in RAM - and the OS is going to keep a copy there as long as it can anyway. The point of SSD caching of journals/writes is that it survives a reboot. If you have a lot more SSD than spare RAM it might save a few seeks as a side effect but why not just add RAM if that matters?
-- Les Mikesell lesmikesell@gmail.com
It's not always easy, or even possible to add more RAM, especially since the storage servers weren't fitted with motherboards that can take more than say 8 or 16GB RAM .