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Re: [Xen-users] Re: Use hard drive as physical mem for xen vm

To: Charles Duffy <cduffy@xxxxxxxxxxx>
Subject: Re: [Xen-users] Re: Use hard drive as physical mem for xen vm
From: "Oliver Neumann [New Identity AG]" <oliver.neumann@xxxxxxxxxxxxxx>
Date: Fri, 11 Nov 2005 21:42:48 +0100
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> If you want to force MySQL to use swap in place of physical memory, why
> not just find the place in the source where it checks for physical (vs
> virtual) memory and modify it to require only that adequate virtual
> memory be available?

I must admit that I am not such a crack programmer, but I think that you
can be sure, that changing such a thing will cost more time/money, then
just investing in hardware. Even if it would only take a day to fix this
(I think that it wouldn't be enough to just comment in a simple if
statement but that this check is made at several stages and that all
other code relies on the fact that the check was made and successful),
this time would cost more money then just buying the RAM.

Anyway - I think that modifying the sources is generally a bad thing -
the whole idea that stands behind testing the application is, that it
should give us a hint, if it can run on a mysql-cluster backend. So if
we modify something in mysql-cluster, results would be worth nothing
because on the live systems we would run with an unmodified version of it.

But I think I've got the point, that this won't work (at least not with
Xen and perhaps not with any other VM) and we will have to invest in

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