Does Cyrus benefit greatly from increased FS buffer cache?

[Rob Mueller]

> Our plan is to throw 12-16GB at it, with the purpose of vastly increasing
> the FS buffer cache (and decreasing I/O).  Or, will that just be a waste
> of RAM?
>
> Some indications are that, yes, it does improve performance notably:
>
> http://blog.fastmail.fm/2007/09/21/reiserfs-bugs-32-bit-vs-64-bit-kernels-cache-vs-inode-memory/
>
> Anyone have any specific thoughts?  Is there any other benefit we might
> see from large memory allocation in 64-bit architecture?

Given that I wrote that blog post, I can only tell you that in our 
environment, 64-bit kernels made a big difference.

Your environment sounds pretty small though, so you might want to see what 
your current load actually is. If it's already < 1, then adding extra RAM + 
a 64-bit kernel isn't going to buy you that much more.

On the other hand, RAM is pretty cheap, and it might be worth doing it and 
going to 64-bit so you don't have to deal with it one day in the future...

Rob