"swap" partition leads to instability?

[jb]

M. V. <bored_to_death85 <at> yahoo.com> writes:

> 
> hi everyone,
> 
> I have a 24/7 network server/gateway with FreeBSD-8.2 on a SSD drive. it's
partitioned as normal (/ , /tmp,
> /var , /usr and swap) for a long time now. But recently I heard from a
FreeBSD expert that I shouldn't have
> swap partition for my server, and having swap partition could make my
server unstable. this was so strange
> for me, and I searched a lot but couldn't find a reason for this claim.
> 
> so my question is simple:
> - could having a "swap" partition, be a bad thing for my FreeBSD server?
and if so, why and in what conditions?
> 
> Cheers!

Hi,

I think your FB expert was up to something. I bet he spoke out of experience.

Swapping by itself can decrease system reliability due to possible data
corruption on swap disk or during two-way transfers, with subsequent incorrect 
RAM and machine crash.

But, swapping is also a symptom, not a problem.
It is never a good idea to let it get to that point.
Badly written, architected, or tuned server app or system are the reason.
Think of RDBMS/SQL server processing real-time on-line transactions and how 
much it goes into setting it up properly for a heavy use.
On a smaller scale, consider this example:
http://blog.jcole.us/2010/09/28/mysql-swap-insanity-and-the-numa-architecture/

jb