32bit vs 64bit Linux

[Eric Shubert]

On 05/31/2013 09:28 AM, keith smith wrote:
>
> Hi,
>
> Even though I have 64bit hardware I always install the 32bit version of
> Linux.  I do so because of the past discussions on this list that made
> me believe the 32bit OS was better because 64bit caching is actually
> slower due to the requirement that the cache be filled to a certain
> point before it is moved.  I think I recall something about the amount
> of RAM having some effect here also.
>
> Using a 32bit version over a 64bit version seems counter intuitive,
> however that is what I have taken away from these conversations about
> 32bit vs 64bit Linux.
>
> I'm using CentOS 6.x on a LAMP server that gets a low amount of
> traffic.   However I may make the jump to Linux on my desktop this
> summer. (this will be my 3rd attempt to become M$ free except one VM so
> I can use IE for testing) I think all of my hardware is 64bit.
>
> So that begs the question, is 32bit better than 64bit or do I not
> understand the issue?
>
> Thank you for your feedback.
>
> Keith
>
> ------------------------
> Keith Smith
>
>
>

Rule of thumb for servers: use a 64-bit host (PVE for example), and 
virtualize everything to run under it. Use 32-bit for KVMs unless they 
need >3G of RAM. OpenVZ contains will of course run 64-bit, as they 
share the kernel.

There are no doubt exceptions to this, but it's a good start.

For a LEMP server, you may want to consider separating EMP into 3 
separate hosts. Doing it this way, you could have both a PHP51 host and 
a PHP53 host (LEMPP?), and let your (E)nginx host determine which one to 
use based on the url (reverse proxy configuration).

Having things on a virtual platform opens up a lot of possibilities you 
don't have otherwise. The list is extensive. :)

-- 
-Eric 'shubes'