What is a "sane" setting for maxdsize when running amd64? it seems many normal suggestions do not apply.

Chuck Swiger cswiger at mac.com
Tue Aug 21 17:13:16 PDT 2007


On Aug 21, 2007, at 4:54 PM, N. Harrington wrote:
> I have seen many posts and suggestions to raise it to 1G. However  
> it seems this only applies to
> i386. By default, on servers I have with 4G of physical memory, and  
> 2X that of swap, I am showing
> a reported datasize limit of 33554432KB. far in excess of even my  
> physical and swap combined!

True...that a big part of what you gain from running in 64-bit mode--  
a huge address space.

>  I have seen suggestions from mysql for maxdsize to be set to 1G.  
> Obviously no such problem with
> amd64?

Right.

>  Is this just a high number chosen to let things run wild?  
> (basically unlimited) I have been
> having some problems with running squid and my servers locking up.  
> I think, from the process
> exceeding my physical memory and the server getting very unhappy  
> trying use so much swap. (since
> it seems the process size is so unlimited)

You should configure squid to use no more than about 60 - 70% of the  
available physical RAM-- ie, set the cache_mem parameter to about 2.5  
or 3GB.

>  Could anyone help shed some light on this for me? If I have a  
> server with 4G of memory, what
> would be a safe /sane allowable maximum for datasize? (assuming a  
> light networking load)

It wouldn't be unreasonable to limit datasize to 3 GB on such a  
machine, assuming that nothing you run will ever need to grow larger...

-- 
-Chuck



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