Q: Should I have swap?

Daniel Carrera daniel.carrera at zmsl.com
Fri Jun 9 08:06:10 UTC 2006


Hello,

Before saying "everybody needs swap!" hear me out :)
This is not for a regular desktop system. The context is unique and 
interesting: I might get involved in a government-sponsored project to 
provide free computers to low-income households. This would be a 
partnership with a city government, and the goal is to reduce the 
digital divide. To make it affordable, we would install Linux thin 
clients into the new social housing being built. Everyone would have the 
option to get a free thin client box that they can plug into an ethernet 
jack on their wall, but they'd be required to take a 10-hour course on 
how to use it.

Now, with that context in mind, I wonder if it really makes sense for 
the server to have swap, or whether that would be detrimental. As soon 
as the server starts swapping, the whole thing would slow down, for 
everybody. It might be better for the computer to say "I'm sorry, there 
are too many users in the system right now...". It'd be similar to 
mobile phones, when everybody is calling at once.

Could someone tell me the consequences of not having swap? What happens 
if I start a program and there is no space for it? I'm sure that the 
system won't just crash, but what /will/ happen?

Does anyone know if Linux can have per-user RAM quotas? And CPU quotas? 
That would be very useful. Especially if they could be setup so they 
activate during peak periods only.

Thank you for your help.

Cheers,
Daniel.
-- 
"It's like a rainbow. Without an observer at a 23 degree angle to
the light reflected a cloud of spherical droplets, there is no
rainbow. The whole universe is like that. Our spirits stand at a
23 degree to the universe."  -- Zoya Boone, Red Mars





More information about the ubuntu-users mailing list