Subject: Re: Midrange machine + NetBSD -- + NUMA.
To: None <>
From: Marc Tooley <>
List: current-users
Date: 02/14/2006 14:49:50
On Monday 13 February 2006 17:08, Thor Lancelot Simon wrote:
> This configuration is similar to that of a number of TNF servers.  It
> should work well.

Superb. I'm pretty stoked at getting NetBSD up on this machine and doing 
some work on it.

> You might want to consider that the MegaRAID supports a battery
> backup module for its cache.  In my experience these are usually well
> worth purchasing even if one thinks the system will never be used
> except when connected to a UPS -- you never know when someone will
> trip over the power cord.

For now, the machine is reserved for scratch/testing use and won't be 
put into full-time duty as a server or other must-be-reliable machine.

> Not as far as I'm aware.  What makes you think this?

Ah, I know why I've this impression now. I ran into the following limits 
not too long ago:

options MAXDSIZ=bytes
options MAXTSIZ=bytes

... and had trouble with a process that wanted to exceed some X GB of 
process memory, even after I added something like 3GB of additional 
swap in my 1GB desktop machine.

Also, I saw posts like yours:

Thor: Can't lock even 4GB on system with 8GB RAM?

... so I guess my memory (haha) is a little suspect.

> One thing to consider may be that if you have the 8GB RAM as 8 1GB
> modules, you will want to reduce the memory bus clock to 333MHz (if
> the BIOS doesn't do so for you automatically).  Current Opteron
> memory controllers can't reliably drive four 400MHz modules at once.

Yes, thank you. This is tremendously helpful: precisely what I'm going 
to be doing.

I've been reading up a bit on Opteron's NUMA, and I learned that 
attempting to allocate the nearest physical RAM to processes that 
preferentially run on a specific CPU was something a few scattered 
handfuls of people are working on for various OSes. That would be