[ILUG] Ram swap

[Michael Watterson]

p.slabiak at linux-services.org wrote:
> Hi all,
>
> in the former linux versions (kernel 2.4.x) the relationship beetwen ram and swap was 1:2. Is it the same with kernel 2.6.x ? I use to install (for me) systems with 2.6 kernel in certain relationship swap/ram
> 1.5:1 but some guys from management want to know exactly.....;=))
>
> thank you very much in advance 
>
>   
To an extent, subject to limitations of OS, it depends on use of 
Computer and the amount of RAM.

When my server had only 12MByte, the paging was very very important.

A 1999 Redhat or NT4 might have been fine with 64M RAM and 64M SWAP.

Going less than 1:1 (or even 1:0)  on most OS, that have LOTS of RAM 
ought to be possible, but for Mortals with LOTS* of RAM the limit is 1:1 
unless you really really understand what you are doing.

*definition of LOTS depends on version of OS and applications running. A 
basic Fileserver may be delirious with only 128M  RAM  but shiny Ubuntu 
desktop with  several OS in Virtual Machines could be very short of RAM 
at 4GByte...


Actually having to use Swap dramatically slows any system. A 4 or 5 
Drives striped with a HW RAID controller can speed Swap speed on a 
multiused fileserver by x100.

So the answer is it is not anything to do with kernel version per se, 
but how much RAM you have and what is running.

-- 
Mike