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From Ron Wheeler <>
Subject Re: hypervisor choice
Date Mon, 13 Nov 2017 14:37:20 GMT
Thanks for your input.
I really like CentOS as well. Partly because I have been using it for so 
long. If I recall, I went from SCO Unix to Mandrake to CentOS (4?).
I am baffled about what changed between the 327 release and the 514 
release. The latest 693 release still gives me the same problem.
It is frustrating to have a machine that boots and runs just fine with 
327 release of CentOS7 but panics if it tries to boot with the latest.

I have this on several machines of differing age. They are all AMD 
processors but the motherboards are different of course.
The installation CD (ISO) of the 514 versions will not even startup so 
it has to be something pretty fundamental.

RedHat has opened up their developer program so I might start to use 
RedHat to see if the problem can be identified in that community.

Thanks again for responding with your advice.


On 13/11/2017 4:36 AM, Dag Sonstebo wrote:
> Hi Ron,
> We regularly use CentOS6 and 7 for KVM, and have never had an issue with non-booting
hosts – but then again our workloads are lab and testing based hence seldom get upgraded
and seldom run for more than a few weeks.
> Saying that – we only ever use the CentOS minimal install, never with GUI – as you
say it’s surplus to requirements in most situations and comes with a lot of baggage. If
you need GUI tools like virt-manager you can either run it on a remote host or do a minimal
local install and open it up over a SSH forwarded X11-session – which all in all means you
don’t have to install the full GUI on each host.
> With regards to Ubuntu – Eric has given a good rundown (personally I have no issues
with Ubuntu – I just find CentOS simpler and reliable).
> Regards,
> Dag Sonstebo
> Cloud Architect
> ShapeBlue
> On 10/11/2017, 19:37, "Eric Lee Green" <> wrote:
>      On 11/10/2017 11:01 AM, Ron Wheeler wrote:
>      > I have been using CentOS for a long time but they seem to have screwed
>      > up the recent updates to CentOS 7 to the point where after updating to
>      > the latest version (originally build 514 and now 683), the system no
>      > longer boots. I have to boot to build 327 which runs fine.
>      >
>      > The idea of having a server that fails after updating is not in my
>      > comfort zone.
>      The other popular choice if you are using KVM on Linux is Ubuntu LTS.
>      The current LTS version is 16.04 which is supported until 2021.
>      Cloudstack runs fine on Ubuntu LTS, but configuring the network may be a
>      bit cumbersome for someone accustomed to the Centos
>      /etc/sysconfig/network-scripts mechanism.
>      In my experience over the years Ubuntu has not been quite as stable as
>      Red Hat Enterprise Linux, *but*, that may have changed with RHEL7/Centos
>      7, where they appear to break things regularly between minor version
>      updates in order to "improve" the system. I, too, ended up with the
>      issue of one of my Centos 7 servers not rebooting after an update, and
>      having to boot it back to an older kernel. I ended up re-formatting and
>      re-installing that server entirely and restoring the system
>      configuration from backups.
>      At this point I'd suggest remaining with KVM on Linux as your
>      hypervisor. It appears to perform better overall than Xen or vSphere and
>      the cost-effectiveness overall cannot be beat, especially if you are
>      buying hardware in bulk and using an automated mechanism to deploy your
>      hardware and the software load upon it so that you don't have to manage
>      it individually.
>      If you are looking for overall reliability (at a cost), vSphere is of
>      course "the" reliable choice (I have some ESXi hosts that have been up
>      for over 500 days, and the last time they went down was during a planned
>      outage to rearrange the racks), but it is very picky about its hardware
>      and likely won't like your current hardware. It can also become somewhat
>      expensive as you add hosts to your vSphere cluster, which is the basis
>      of a CloudStack pod (rather than the individual hosts). It's also as
>      much as 10% slower by my measurements under many workloads because they
>      make numerous decisions that improve reliability at the expense of
>      performance. Still, for customers that value reliability above all else,
>      vSphere is a brick -- reliable and pretty much bullet-proof.
> 53 Chandos Place, Covent Garden, London  WC2N 4HSUK
> @shapeblue

Ron Wheeler
Artifact Software Inc
skype: ronaldmwheeler
phone: 866-970-2435, ext 102

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