On 11/16/2016 04:17 PM, Kevin Fenzi wrote:
On Wed, 16 Nov 2016 14:17:46 +0100
Mikolaj Izdebski <mizdebsk(a)redhat.com> wrote:
> Michael Simacek pointed out that koschei-backend01.phx2 has 20 GB of
> physical memory, while Ansible inventory vars specify only 4 GB.
>
> Does anyone know where this difference comes from? Did anyone increase
> VM settings without committing them to Ansible git repo? If so, what
> was the reason?
It might have been me... bumping the memory up to see if it helped it
with memory usage. ;( But usually when I make those changes, I also
make them in ansible, and I don't recall making this one, so perhaps it
was someone else. ;(
That won't help much with swap usage by itself. We are limiting RSS for
systemd services, any virtual memory beyond limit (currently 3 GB) is
swapped to disk. So it ends up with swap usage above 80 %, but mostly
free physical memory - below 25 %.
Anyhow, the way we setup hosts in ansible they have the memory they
are
set for in vars, and also we set max_memory to 5* that value. ie, this
host was set for 4GB memory, so max was 20GB and it was dynamically
increased to that.
Right, now I remember seeing this.
Shall I decrease it back to 4GB? (That may need a reboot).
Not needed right now. I'll be reinstalling it as Fedora 25 after GA.
When reinstalling I would like to add more swap (4 GB instead of 2 GB;
that would require a custom kickstart, IIUC) and set max_mem_size to 4
GB. Any reason not to do this?
Thanks,
--
Mikolaj Izdebski
Software Engineer, Red Hat
IRC: mizdebsk