Re: postgresql + apache under heavy load

On Wed, 21 Jan 2004, Richard Huxton wrote:

> [I noticed you were running X and mozilla (on top of gnome?). If you don't 
> need them, close them - that can free up to 64MB, depending on what you're 
> running]

Note that if you've got a 64 Meg memory video card, and X uses 4 megs of 
system ram, it will show, in linux, as using 68 Megs of ram.  Turning off 
X, however, will only free up the 4 megs of system ram, not the 64 on the 
video card.  so, it's not uncommon for folks to see a modern video card in 
their system, look at top, and go "geeze, X is a total memory hog" when in 
fact it's just that linux / top count the video memory as part of the 
memory allocated to X.

That said, I'd at least run a less heavyweight window manager like 
afterstep or twm, not gnome or kde on a box like that one.

> I don't think you've got a RAM shortage, I think your settings are too small 
> and you're running out of I/O bandwidth. If you run "vmstat 5", what does it 
> show - you're interested in the i/o section: blocks in (bi) and out (bo) as 
> well as memory.

Also, look at si/so (swap in and out) to monitor swap activity.  If those 
numbers are low, then swapping isn't an issue...