Re: [gentoo-user] Re: Disabling swap & mounting /tmp on tmpfs = new standard?

[Grant]

>>>> I recently disabled swap and mounted /tmp on tmpfs for a netbook since
>>>> the SSD is so slow, and now I'm wondering if that would be a wise move
>>>> for all of my Gentoo systems.  In what type of situation would it be a
>>>> bad idea?
>>>>
>>> Instead of disabling swap, just make it small (like 32MB or something;
>>> whatever the smallest allowable partition size is).  The kernel needs
>>> swap to operate optimally, even if it's extremely small.  Just make sure
>>> it's there.
>>>
>>
>> Hmm, on this old box I noticed swap was using more than 135,000K earlier today
>> as I was emerging xulrunner and ImageMagick.  I think that the size of swap
>> is relevant to the memory size that the box in question has.  Not all
>> machines have found their way to 2G RAM yet ... ;)
>>
>>
>
> Don't forget that you can set swapiness too.  This is set in
> /etc/sysctl.conf and for mine I have this:
>
> vm.swappiness = 30
>
> The lower the number, the less chance of it using swap.  If it is set to
> 90, it will use a lot of swap which is fine if you have little ram or a
> really fast drive.  If it is set to 30, then it will not use swap unless
> it is basically out of ram.
>
> With the setting of 30, mine uses swap when compiling OOo or some other
> large package or if I am opening a TON of pics.  Otherwise, swap is at 0
> or close to it even after being up a long time.  I have 2Gbs here tho.
> Your mileage may vary.
>
> Dale

Thanks Dale.  Should "vm.swappiness = 30" work well on all systems?
My Gentoo systems have vastly different specs and duties so I love
tweaks that always improve things.  It sounds like /tmp on tmpfs is
one of those.

- Grant