[ale] that same darn NFS problem SOLVED

[Michael D. Hirsch]

On Monday 17 February 2003 02:30 pm, Chris Ricker wrote:
> On Mon, 17 Feb 2003, James P. Kinney III wrote:
> > With a 2.4.x kernel and RAM <=4G swap=2xRAM
>
> That's not necessary. There was a bug in early 2.4.x that required
> swap=2xRAM for decent performance, but that's long since been fixed...
>
> You need enough swap to hold your working set. That could be anything
> from no swap to gigabytes, depending on what you do on that system....

Right, but the rational I heard is 

1.  Having swap doesn't hurt
2.  Unless you have so many processes and so much swap space that you get 
swap bound
3. swap = 2 x RAM is a reasonable heuristic.  If you use much more than 
that you are probably swap bound, but up to that amount could really 
happen without getting swap bound.

Obviously one can create loads that would be usable with more than that 
much swap in use.  One could also create loads that are unusable with less 
than that much in use.  It is just a rough guess that often works okay, 
and few of us have the time or ability to really do an analysis of our 
swap needs.

Michael
_______________________________________________
Ale mailing list
Ale at ale.org
http://www.ale.org/mailman/listinfo/ale