Re: very strange reaction of the md disks

On Tue, 03 Jun 2008 11:31:05 +0400
The Ghost <the-ghost@xxxxxxxx> wrote:

Hello,

Maybe I just don't understand something, but anyway, it looks really
odd.

I have a machine with 2 Gb RAM with a clean newly-installed
FREEBSD-7.0-RELEASE. I make two 300-MB mdconfig disks and populate
them, and when the first one was already full and the second one is
only half-full, I get a kernel panic "not enough memory". I wonder
where did 1,5 Gb go??

Try using swap-backed md devices instead. With both malloc and swap
devices the data is stored in ram and paged-out to swap as needed, but
it helps with some of the malloc limitations.

I'm using a 2.7GB /tmp directory with 1.6GB of ram and have not had any
problems. I don't actually see any swap usage unless I put a lot of
data on the device, otherwise I can even do a swapoff.
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