<p>If there is >16Gb RAM and people are sweating about holding back RAM + 2GB for swap, maybe a bigger hard drive is a good idea.</p>
<p>When ram WAY more expensive, swap space was used often. The rest of the system was so slow it was an irritation and not an impediment. Modern systems are nearly 3 orders of magnitude faster while drive access has only increased 10x. <br>
So for a small, 1 or 2 spindle server, where suspend and hibernate are not options, less swap than ram makes sense.<br>
A laptop needs ram+ for swap for laptop things.<br>
Big servers with many local fast spindles can afford ram+ swap spread over multiple drive in chunk sizes equal to a combination of page size and drive page suze.(crap. Wrong term. Large inode size, um, crap, brain fart on drive transfer data chunk).<br>
Here's the fun part: if your swap is on lvm space, you can change the size based on observed need. <br>
Fun part #2: unused swap space is pretty painless to have lying around except for the OCD crowd that tends to whine on the mailing list :-) For them it's lile slowly running their fingernails down a mile long chalkboard.</p>
<div class="gmail_quote">On Oct 12, 2011 9:43 PM, "Tavarvess Ware" <<a href="mailto:tavarvessware@gmail.com">tavarvessware@gmail.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<p>Scott I read the ram x 2= swap in my Linux classes as well and have generally followed that, but with memory soaring as it has lately i am starting to rethink that. A system 48gigs of memory would be 96 in swap..... I wonder if te old format has changed and I haven't heard yet.<br>
</p>
<div class="gmail_quote">On Oct 12, 2011 9:32 PM, "Scott Castaline" <<a href="mailto:skotchman@gmail.com" target="_blank">skotchman@gmail.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
On 10/12/2011 04:14 PM, planas wrote:<br>
> On Wed, 2011-10-12 at 15:13 -0400, Geoffrey Myers wrote:<br>
>> 'Just so you all know, when determining how much space to assign to<br>
>> swap: Swap isn't just used for paging or virtual memory management; swap<br>
>> is also used by power management for suspend-to-disk (hibernation). '<br>
>><br>
>> I seriously don't know, so I'm asking.<br>
>><br>
><br>
> I have seen that a good swap size is ~1.5x the RAM.<br>
> --<br>
> Jay Lozier<br>
> <a href="mailto:jslozier@gmail.com" target="_blank">jslozier@gmail.com</a><br>
><br>
><br>
><br>
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I remember from somewhere that upto 2GB use 2.0x RAM above 2GB of RAM go<br>
with 1:1 ratio so 4Gb RAM = 6GB swap. I don't remember why 2x on the<br>
first 2GB and this goes back to when 4GB was a lot on pre-configured<br>
retail boxes. So like Geoffrey I can't see having 18GB of swap for a<br>
16GB machine.<br>
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