FreeBSD 5.x performance tips (ISC)

Jon Noack noackjr at
Mon Jan 12 17:32:08 PST 2004

First place I'd look would be the performance@ list, but that's just me ;-).


On 1/12/2004 6:59 PM, Peter Losher wrote:
> Hash: SHA1
> So, as many of you know ISC hosts a quad-Xeon server running FreeBSD 5.1
>  (-p10 to be precise) which hosts half of, etc.  Many of you 
> helped out with some teething pains w/ virtual memory sizes, and kernel 
> panics.  Thanks :)
> The issue with the system now is that while the kernel is SMP-aware, and as I 
> watch 5.2-REL get downloaded today, this system is like the arm muscle that 
> is developed to lift that barbell, but not enough blood is getting 
> everywhere, so the barbell is slowly moving up while the muscle cramps like 
> hell.  In this case the system is ~70% idle, and around 150 processes are 
> locked and the performance starts to seriously decrease at times. (Entropy 
> stops getting collected, etc.)  Not a pretty sight.  The CPU's are all 
> spinlocking on an I/O channel. so high I/O translates into artificial high 
> cpu and load averages.
> So where can I look for pointers on how I can squeeze better performance out
> of this configuration? I already have the usual sysctl entries installed.
> Any chance moving to 5.2 will help the situation? 
> Best Wishes - Peter

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