SWAP priority

[Bob]

On Monday 02 October 2006 09:14, Chuck Swiger wrote:

> The swap system knows how to interleave data between the additional swap
> areas relatively efficiently, 

Yes I discovered that. The additional swap space was instantly used as soon as 
I activated it; and the added swap improved things measurably. Does the swap 
system take into account current disk activity when it decides to use a 
particular swap?

> that you need to use more than 2GB of swapspace on a machine with 1GB of
> RAM, you should add more RAM, not more swapspace....
 
It is on order. 

The basis for my question about swap priority was based on an observation that 
the slowdown was due to swapping AND heavy disk usage. I noticed that when 
snapshots were being made on the main drive (the one I am using all the 
time), all other processes went to slow-mode. You see, the lack of enough 
memory caused the system to swap, and it swapped to the heaviest used raid 
array. I thought if I could force the system to swap to the other raid array 
(much less used) with the new swapfile, things would improve even more.

All will be cured when more ram is installed, but I thought it would be 
interesting playing with swap priority.
 
Bob