HP Requesting SWAP = RAM

[Stephen John Smoogen]

On Tue, Apr 27, 2010 at 6:47 AM, Michael Weber
<mweber at alliednational.com> wrote:
> Good morning!
>
> If memory serves, the kernel goes into emergency memory saving mode when it detects the available swap space is less than 50% of physical ram.  It does this to keep from crashing should memory usage go up.  There is a pretty steep performance hit when it does, as you've found out.  The kernel really does want swap => ram.  It likes its elbow room.  Even if you have enough memory that you should never need to swap out a memory page, you still have to have the swap space available.
>
> Swapping the drives is one way to get the space needed, or you could stay with the iSCSI space.  This assumes that you really will never need to use the swap, because iSCSI speed isn't near what DAS is.  If there is even a remote chance your memory usage will go up, grab the drives now.
>
> IMHO, of course!

Interesting. I don't know of any such mode with the 2.6 kernels.. but
it could be called something else.

To be honest, its the vendor's code and they can do what they damn
well please. If they want you to dance 4 times in front of the camera
in a pixie suit.. thats the breaks. At that point all one can do is
post to a list so that people googling about the problem or whether to
buy the software will ever want to.

On the other hand I have known that some of these 'tests' are done
inside of a script or a program that can be hacked to change what its
looking for. You lose all support if you run into issues.. but it can
be done for a lot of programs. At this point one needs to go through
and see what the program is doing, where and how.

In the case where you need to keep your warranty, and don't have any
leverage with HP or the person paying your salary... order a bunch of
local disks of 256GB or so. Put them in the box call it all swap and
use the isci for whatever else you needed.


-- 
Stephen J Smoogen.
“The core skill of innovators is error recovery, not failure avoidance.”
Randy Nelson, President of Pixar University.
"We have a strategic plan. It's called doing things.""
— Herb Kelleher, founder Southwest Airlines