CloudLab Utah c6620 downtime - August 6th

[Aleksander Maricq]

Hi all,

We are planning an all-day downtime of the c6620 machines at CloudLab Utah on August 6th from 9 AM to 6 PM MDT.  Existing experiments using the c6620 machines will not be able to be extended past August 6th at 9 AM.  None of the other hardware types at CloudLab Utah should be affected by this.

During this time, we will be moving the c6620 100Gb experiment net wires to new switches, which will allow the 100Gb interfaces on the c6620 machines to be synchronized using PTP.  This feature had been planned since the beginning of this expansion, but unforeseen limitations with our current switch prevented us from rolling this out until we got new switches.  For reasons both technical and non-technical, we want to make this move as soon as we are able to.  While we have the nodes out of service, we will also be upgrading the firmware on all of the c6620 machines to their latest available versions.

The side-effect of this change is that the c6620 100Gb interfaces will have to be split between two switches, where they were all on the same switch before.  That means that some pairs of nodes will have more switch hops between them than before, so if you want to avoid interswitch links in your experiment, you can specify this in your profile using `link.setNoInterSwitchLinks()`.

Let us know if you have any questions or concerns.

Best,

 - Aleks

[John Ousterhout]

Hi Alexs,

Will the c6620 reconfiguration affect the switch changes we made to
enable priority queues for Homa? For example, are the new switches a
different type where I'll need to re-figure out how to enable the
priority queues?

-John-

> --
> You received this message because you are subscribed to the Google Groups "cloudlab-users" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to cloudlab-user...@googlegroups.com.
> To view this discussion visit https://groups.google.com/d/msgid/cloudlab-users/53f6b0bd-26a8-4e2b-a84b-8a658fb72587n%40googlegroups.com.

[Aleksander Maricq]

Hi John,

The new switches are two Z9432F-ONs instead of a Z9664F-ON.  The same configuration should be possible to put on these new switches, but we can work with you in advance of the move to make sure that's the case.

Best,

 - Aleks

[John Ousterhout]

Sounds good. If you can apply the current patches to the new switches, then once the new switches are up I'll run a quick experiment to see if the priority queues are working. If not, we can coordinate to make whatever adjustments are needed.

-John-

To view this discussion visit https://groups.google.com/d/msgid/cloudlab-users/f43f7fb3-efe7-42ee-9a6e-98e31a6b2726n%40googlegroups.com.

[Aleksander Maricq]

Hi all,

We have concluded our work for this downtime.  Let us know if you run into any issues.

Best,

 - Aleks

[John Ousterhout]

Hi Alexs,

I now have an experiment running on the c6620 cluster, and it appears to me that priorities are not working. Can you double-check to make sure you applied the switch commands to enable priority queues?

Thanks.

-John-

To view this discussion visit https://groups.google.com/d/msgid/cloudlab-users/790ec5c7-5d3c-44e1-96c3-a1ef46ea8b6cn%40googlegroups.com.