Re: Pre-allocation of shared memory ...

Lamar Owen wrote:
> On Friday 13 June 2003 11:55, Josh Berkus wrote:
> > Regrettably, few of the GUI installers for Linux (SuSE or Red Hat, for
> > example), include adequate swap space in their "suggested" disk formatting.
> > Some versions of some distributions do not create a swap partition at all;
> > others allocate only 130mb to this partition regardless of actual RAM.
>
> Incidentally, Red Hat as of about 7.0 began insisting on swap space at least
> as large as twice RAM size. In my case on my 512MB RAM notebook, that meant
> it wanted 1GB swap. If you upgrade your RAM you could get into trouble. In
> that case, you create a swap file on one of your other partitions that the
> kernel can use.

Oh, that's interesting. I know the newer BSD releases got rid of the
large swap requirement, on the understanding that you usually aren't
going to be using it anyway.

What old BSD releases used to do was to allocate swap space as backing
_all_ RAM, even when it wasn't going to need it, while later releases
allocated swap only when it was needed, so it was only for cases
_exceeding_ RAM, so your virtual memory was now RAM _plus_ swap.

Of course, if you exceed swap, your system hangs.

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