Please note that the maxmbps parameter of mmchconfig is not part of the QOS
features of the mmchqos command.
mmchqos can be used to precisely limit IOPs.
You can even set different limits for NSD traffic originating at different
nodes.
However, use the "force" of QOS carefully! No doubt you can
Hi
Writing from phone so excuse the typos.
Assuming you have a system pool (metadata) and some other pool/s you can
set limits on maintenance class that you done already and on other class
that would affect all the other ops. You can add those per node or
nodeclass that can be matched to what
Hi all,
My experience with MaxMBpS was in the other direction but it did make a
difference. We had lots of spare network bandwith (that is, the network
was not the bottleneck) and in the course of various GPFS tuning it also
looked like the disks were not too busy, and the NSDs were not too
The man page indicates that maxMBpS can be used to "artificially limit how much
I/O one node can put on all of the disk servers", but it might not be the best
choice. Man page also says maxmbps is in the class of mmchconfig changes take
place immediately.
We've only ever used QoS for throttling
IIRC, maxMBpS isn't really a limit, but more of a hint for how GPFS should
use its in-memory buffers for read prefetches and dirty writes.
On Mon, Jun 17, 2019 at 09:31:38AM -0700, Alex Chekholko wrote:
> Hi Chris,
>
> I think the next thing to double-check is when the maxMBpS change takes
>
Hi
I would really look into QoS instead.
--
Cheers
> On 17 Jun 2019, at 19.33, Alex Chekholko wrote:
>
> Hi Chris,
>
> I think the next thing to double-check is when the maxMBpS change takes
> effect. You may need to restart the nsds. Otherwise I think your plan is
> sound.
>
>
Hi Chris,
I think the next thing to double-check is when the maxMBpS change takes
effect. You may need to restart the nsds. Otherwise I think your plan is
sound.
Regards,
Alex
On Mon, Jun 17, 2019 at 9:24 AM Christopher Black
wrote:
> Our network team sometimes needs to take down sections
Our network team sometimes needs to take down sections of our network for
maintenance. Our systems have dual paths thru pairs of switches, but often the
maintenance will take down one of the two paths leaving all our nsd servers
with half bandwidth.
Some of our systems are transmitting at a
