[CentOS-virt] AWS c5d.9/18xlarge instances not supported

[Nico Kadel-Garcia]

On Sat, Jul 14, 2018 at 3:11 PM, Henry Finucane <h.finucane at gmail.com> wrote:
> On Sat, Jul 14, 2018 at 5:22 AM Nico Kadel-Garcia <nkadel at gmail.com> wrote:
>> See above. Also, the base CentOS 7 3.10.0 kernel is becoming a bit
>> dated: it's 5 years old now. If you have time: can you set up a
>> smaller instance, do kernel updates on top of a CentOs 7 AMI, and see
>> if *that* AMI is compatible with the new instances? Might make for an
>> interesting test and get you a working AMI.
>
> I did this with CentOS 6 at some point, and it's worth noting that
> you'll have to build your own AMI from scratch, you can't just update
> the existing AMI- the base AMI's lack of support "taints" derived
> ones.

There Are Ways(tm). One of my favorite is to link a LiveDVD image to
the VM built from the messed up or out of date OS image, mount the
storage for the messy host, and do the updates on a chroot cage to
*that*. In this case, there instances of the same class, just
different sizes, that are apparently tested and approved. I'd stage a
build to one of the approved instance types and do the updates
*there*, then take a snapshot.

> I used packer's chroot builder, it was pretty reasonable and you can
> find examples online to help you get started.

Heh. I wrote tools that did something like this for hardware testing,
creating a base tarball image much like "mock" does and applying it to
new hadware configurations from DHCP and kickstart, and even one that
could be downloaded and run to upgrade from a local tarball. That was
in... 2000, and was used on roughly 20,000 systems that year for an OS
update. It's still faster than most virtualization "disk image" based
clones from a golden image.