[Ci-users] AltArch support in CI (status update)

Tue Jul 25 15:45:51 UTC 2017
Brian Stinson <brian at bstinson.com>

On Jul 14 16:25, Fabian Arrotin wrote:
> Hi,
> 
> Just starting a thread on the list so that various projects having a
> need to test their builds on AltArch (aarch64/ppc64/ppc64le) within CI
> are aware of the following :
> 
> Thanks to Brian, who coordinated with several folks, we'll be able soon
> to provide access to aarch64/ppc64/ppc64le nodes within ci.centos.org.
> 
> So far we have configured/deployed/tested ppc64/ppc64le in the
> environment, so that we can automate the whole thing happening behind
> the scene (basically ansible being called for this, the same way it's
> actually done for x86_64).
> 
> The last thing to do is now to make Duffy
> (https://wiki.centos.org/QaWiki/CI/Duffy) aware of those "other arches"
> nodes to be able to
> - hand over those nodes on specific request
> - reinstall those automatically by calling correct playbooks
> 
> Worth noting that due to the amount of physical nodes for those
> AltArches, we'll not be able to provide you access to bare metal nodes,
> but rather to VMs running on those (at least for ppc64/ppc64le).
> 
> That shouldn't be a problem as we'll be able to distribute resources so
> that you'll have multiple vcpus per VM, and for Power8, our hypervisors
> are installed with CentOS 7 ppc64le, that uses the kvm_hv module. That
> then means that it's possible to use nested virt (if needed) as it will
> then use the kvm_pr for this, slower, but works
> (http://wiki.qemu.org/Documentation/Platforms/POWER)
> 
> If you have remark/comments, feel free !
> 
> -- 
> Fabian Arrotin
> The CentOS Project | http://www.centos.org
> gpg key: 56BEC54E | twitter: @arrfab
> 




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A couple of us spoke about this the other day and decided that we would
take the following approach to sizing VMs on altarch hardware: 

Our Openstack instance, CICO Cloud, has the following VM sizes
available:

 Name   |  RAM | Disk | Ephemeral | VCPUs |
--------+------+------+-----------+-------+
 tiny   | 1940 |   10 | 0         |     1 |
 small  | 3875 |   20 | 0         |     2 |
 medium | 7750 |   40 | 0         |     4 |
--------+------+------+-----------+-------+

We will duplicate the same sizes for Libvirt VMs on altarch hardware,
but in order to take advantage of the incredible memory density on
these machines, we'll be adding a few flavors for libvirt nodes -only-:

 Name         |  RAM  | Disk | Ephemeral | VCPUs |
--------------+-------+------+-----------+-------+
 lram.tiny    | 11444 |   10 | 0         |     4 |
 lram.small   | 15258 |   20 | 0         |     8 |
 xram.tiny    | 22888 |   10 | 0         |     4 |
 xram.small   | 38750 |   20 | 0         |     8 |
 xram.medium  | 77500 |   40 | 0         |    16 |
--------------+-------+------+-----------+-------+

The aarch64 kit will allow: tiny,small,medium,lram.tiny,lram.small
The ppc64le kit will allow: all that you see above

What I'd like from you all is comments about the {l,x}ram sizing. We
have enough capacity to host quite a few of these VMs. Since this is
easy to change and we haven't opened this up to users yet, I'll continue
working on the provisioning side with this scheme in mind.

Cheers!

--
Brian