Re: [gentoo-user] Questions re swap and hibernate interaction on 8 gig machine

[Peter Humphrey]

On Monday 21 June 2010 23:04:14 Walter Dnes wrote:
>   I just got a brand new custom-built 8 gig machine.  There's an
> outfit in north Toronto that has MSI motherboards with PS/2 ports,
> so I can keep my genuine IBM PS/2 clickety-clack-keyboard;
> wooooohooooo.  And the integrated Intel graphics chip has *BOTH VGA
> AND DIGITAL OUTPUTS*!

I have a box with those two outputs, but I found that the display card 
stopped working if I connected both outputs to the same, dual-input 
monitor. Just a cautionary note in case you have some need for that.

> Anyhow, I have 8 gigs of ram on the sytem (will obviously be 64-bit
> Gentoo) and I want to know how much swap I need.  The general rule of
> thumb is twice the ram.  In this case, it would be 16 gigs.  I think
> that it may not need swap when up, unless I do some heavy duty stuff.

With 8 GB RAM I recommend putting /tmp into a tmpfs, thus:

tmpfs         /tmp          tmpfs   nodev,nosuid,size=16G   0 0

This box has 4 GB RAM, which is never all occupied unless I'm compiling 
something big, such as Open Office. I created two swap partitions: a 2G 
and a 20G. The 2G partition has pri=10 and the 20G has pri=1. Now the 
small swap will be used in ordinary operation (though it never is, as 
far as I know). When I'm emerging Open Office, the big swap is added when 
it's needed, and /tmp is rolled out to swap when it grows too big for 
the physical memory.

You may think the small swap is an unnecessary complication, and I dare 
say it is, but when you have lots of space, why not play in it? Anyway, 
it seemed like a good idea at the time.

(Actually, I've made it more complex still, by duplicating the swap 
arrangement on the second disk so that the kernel has maximum flexibility 
and can use the most efficient device at any time.)

> My main concern about a swap partition is how much I need for
> hibernate-to-disk to work.  Is there a rule about this, or should I
> simply allocate 16 gigs out of my terabyte drive, and play it safe?

Can't help you there; sorry.

-- 
Rgds
Peter.          Linux Counter 5290, 1994-04-23.