On Thursday, July 07, 2011 03:57:04 PM Brunner, Brian T. wrote:
centos-bounces@centos.org wrote:
On 07/06/11 5:40 PM, John J. Boyer wrote:
When I first installed my CentOS system the machine had only 1 GB. the swap memory was set to 2 GB Now the machine has 4 GB but swap is still 2 GB. With that much memory maybe it doesn't matter, but it sure looks odd. Is there any way to change it?
add another swap extent via the swapon(8) command.
but, 2gb is plenty of swap for a 4gb system, anyone who insists on swap
= physical memory is smoking something left over from the 1970s.
This is true both literally and figuratively.
Actually there are cases where you do want swap ~= physical (even though you wont be "using it". For example, if you need to increase the ulimit for stack size (some apps need this) then for a normal fork the kernel will need (free phys + free swap) > this.
So in the end you'll need a bit more swap then your required stack size limit.
Worth noting is that if you set it to unlimited then you don't need to reserve any swap for it...
/Peter