Re: Swappiness in Buster

[songbird <songbird@anthive.com>]

Martin Reissner wrote:

> Hello,
>
> ever since upgrading machines to Buster the vm.swappiness sysctl
> parameter doesn't seem to do anything anymore and regardless on how I
> set it via sysctl or directly in /proc the system behaves as it would
> have a pretty high swappiness and thus is swapping out quite a bit under
> load, using the memory mostly for buff/cache.
>
> To make this clear, I'm seeing no performance degradation and there is
> not much swapping in done, I'm merely wondering why this behaviour has
> changed and if there's a way to make it work as before again. Also I'd
> be happy to know if anybody else is experiencing this as Buster has been
> out for a while now and I found some information on this ie. other users
> reporting the same issue, but not really a lot.
>
> Now if you're asking why I would configure swap if I don't want it to be
> used, the answer is monitoring and failsafe. I usually set the
> swappiness to 1 so to only swap if the box runs out of memory and then
> trigger an alarm to let us know something is up. This is much more
> convenient than the oomkiller striking down a mysqld process just
> because it was allowed to use a bit too much memory.

  i haven't noticed any issues with my desktop system set
to 5, but i rarely if ever get much swapping going on 
anyways.  i'm not using buster but using testing.

  if you are running a database oriented server i think
the recommendation would be to set it to 0 or 1.


  songbird