(panic) Lots of network memory needed

[Karim Fodil-Lemelin]

Hello,

	From kernel tuning page (http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/configtuning-kernel-limits.html) 

Some sentence about nmbclusters says: 

	"Under no circumstances should you specify an arbitrarily high value for this parameter as it could lead to a boot time crash."

Now I want to push the limits where I need 4KB buffer for each of the 32000 connections I want this server to handle. If I do the math:

(32000 (conns) * 4 (KB/buffer) * 2 (buffer/conn)) / 2048 (KB/cluster)

	= 128000 clusters

So I set this arbitrary high value in loader.conf under (kern.ipc.nmbclusters) and no surprises I get panic: pmap_enter invalid page directory pdir=0x3cb063, va=0xfff800

(va has a weird address here)

I know I am pushing the limits here but I have plenty of memory (2GB) on this system (after all its just 250MB for network memory ;) and this is mainly just experimentation. 

I would like some pointers toward fixing this. Is there another variable tied into this (I guess so)? Could anybody points me to a technical document that would explain the relationship with that (those) other(s) presumed variable(s)?

Thank you,


Karim