Re: [gentoo-user] mysqld invoked oom-killer

[Grant]

>> Hi Alan, I think it was your advice I took a long time ago when I
>> stopped installing new machines with a swap partition and disabled it
>> on my already-installed machines.  Some time later, others on this
>> list caught wind of what I'd done and told me I was an idiot.  Is
>> there a consensus on this?  If the drawbacks and advantages of using
>> swap cancel each other out, I won't use it.
>
> I think it's basically like this:
>
> No swap = If you run out of memory, OOM-killer starts killing things
> "randomly" and stuff breaks.
>
> With Swap = System does not run out of memory, so things don't die,
> but it runs poetntially much slower during that period of high memory
> usage depending on your disk speed and how heavily it is leaning on
> swap at that moment (if it is actively trying to use more data in RAM
> than you physically have RAM for, it's a total slowdown disaster). If
> it's a case of run-away memory usage, it'll run out of swap, too,
> anyway, so having swap in that case only delays the OOM-killer.
>
> I think if you have 4GB of RAM you shouldn't need any swap under
> normal circumstances. I have a gentoo box with just 256MB of RAM
> that's running web server (apache + php), mail server (postfix +
> dovecot), and database (mariadb), and it works fine if i disable swap.
> I do normally have swap enabled on it, though, because emerging
> sometimes uses a lot of RAM.

Thanks Paul.  I'm leaning toward leaving swap disabled.  So I'm sure I
have the concept right, is adding a 1GB swap partition functionally
identical to adding 1GB RAM with regard to the potential for
out-of-memory conditions?

- Grant