[lug] Convert swap from raid0 to raid1

[dio2002 at indra.com]

> Besides, if your system is swapping you're already trading off 3 orders of
> magnitude performance, so who really cares if even if swap were 2000x
> slower than RAM rather than just 1000x.
>
>>thoughts.  i worried about the performance hit when i decided to go that
>>route but everything is a tradeoff.  availability versus performance in
>
> If you are worried about performance, disable swap or make it very small.

In the process of working through this, i learned it was very possible to
turn swap on and off on a running system.  however, up until now, i always
thought that swap was a requirement and that you had to have it.  it's
been in the default install from as far back as i can remember.  probably
as a legacy from the days of low end hw and small ram footprints that are
not longer issues today.

thanks for that info that's probably common knowledge to others.

> Unless your application really just *HAS* to complete, no matter what,
> it's
> probably better off to have the system kill processes, than for it to
> start
> thrashing and become unresponsive.  A system that is unresponsive because
> of thrashing for 15 minutes might as well be down...

yeah good points. either way you're going to have to fix the underlying
problem.