Hi Chuck,

You may want to look into using tmpfs for some of your mounts. Mounting /tmp, /var/tmp, etc in RAM should reasonably reduce the writes to disk. 

Cheers,
Lincoln


On Jun 10, 2013, at 11:42 AM, Chuck Munro wrote:

> Hello all,
> 
> I have been running a couple of KVM servers on SL6 for quite some time, and have been very happy with performance.  One of these machines hosts five instances of firewall software (a mix of pfSense and m0n0wall) and I'd like to port this configuration to SSDs (RAID-1) to increase reliability.
> 
> My question is how do I minimize writes to the disk array?  Is it possible to significantly reduce disk writes once the host SL6 OS has booted up and the guest OS's are running?
> 
> The current hard-drive-based box has lots of RAM (8 GBytes) and each guest has a pretty small footprint, so swapping has never been invoked.  So far the current SL6-based firewall pretty well runs itself with very little effort on my part, so things like syslog are usually not monitored much.  Can the /var filesystem be safely mounted from a file server or does it have to be on a local drive during bootup?
> 
> I do let logwatch and logrotate run on the current box (with hard drives) but I'm tempted to reduce logging to a bare minimum and rotate logs to /dev/null
> 
> At this point it's all somewhat academic, but I'd like to consider the possibility of reducing heat and eliminating as many moving parts as possible.  I like KVM and would prefer to stick with it.  I don't have the luxury of running a bunch of embedded diskless firewall boxes, unfortunately.
> 
> Your suggestions??
> 
> Thanks in advance,
> Chuck