Using CentOS-6.x on KVM-hosts - what are the threats?

[Vladimir Melnik <v....@uplink.ua>]

Dear colleagues,

I've just realized that my KVM-hosts are running CentOS-6 whilst it's
recommended to use CentOS-7 with the new versions of ACS. Everything
seems to be fine (some of these hosts are working for a few years),
hosts are working and things are great, but I'd like to ask a couple of
questions. Here they are.

(1) How high is the chance of the next version of ACS (4.10 or 4.11)
will be incompatible with CentOS-6? Should I worry about that and
consider upgrading to CentOS-7 immediately?

(2) What ACS features I'm missing because of that? I suppose that I'll
be disappointed if I try to limit a VM's IO-consumption, just because
old good QEMU-0.9 won't support it. Am I right? Are there other things
that are worth of upgraging to CentOS-7?

Thank you very much in advance for your replies!

-- 
V.Melnik

Re: Using CentOS-6.x on KVM-hosts - what are the threats?

[Simon Weller <sw...@ena.com>]

Vladimir,


To answer your immediate question, I don't think you're at major risk by staying on Centos 6 in the medium term. Centos 6 will be supported by Centos until Nov 30th, 2020. In terms of what ACS will support, I don't think it has been discussed on the list for a while. There will be a point at which it won't make sense based on the the lack of features available and personally I think we might be starting to get close. As of 4.9, we now have a LTS release out and that most likely will be the release most Centos 6 users will stay on.


We have been running Centos 7 hosts now for a while and it's a lot more stable in our opinion and just works out of the box, especially with storage backends such as Ceph.

If you've been running Centos 6 for a few years,  you might be be getting close to a hardware refresh anyway. If you are, you could build a new Centos 7 based cluster and them migrate primary storage to a new cluster.

- Si

________________________________
From: Vladimir Melnik <v....@uplink.ua>
Sent: Friday, February 17, 2017 12:53 PM
To: users@cloudstack.apache.org
Subject: Using CentOS-6.x on KVM-hosts - what are the threats?

Dear colleagues,

I've just realized that my KVM-hosts are running CentOS-6 whilst it's
recommended to use CentOS-7 with the new versions of ACS. Everything
seems to be fine (some of these hosts are working for a few years),
hosts are working and things are great, but I'd like to ask a couple of
questions. Here they are.

(1) How high is the chance of the next version of ACS (4.10 or 4.11)
will be incompatible with CentOS-6? Should I worry about that and
consider upgrading to CentOS-7 immediately?

(2) What ACS features I'm missing because of that? I suppose that I'll
be disappointed if I try to limit a VM's IO-consumption, just because
old good QEMU-0.9 won't support it. Am I right? Are there other things
that are worth of upgraging to CentOS-7?

Thank you very much in advance for your replies!

--
V.Melnik

Re: Using CentOS-6.x on KVM-hosts - what are the threats?

[Vladimir Melnik <v....@uplink.ua>]

Thank you for this article, your piece of advice helped me very much some time ago and I always install cloud-qemu-img to each host since 2014 when I had moved from 2.2 to 4.2 :)

On Fri, Feb 24, 2017 at 10:30:38AM +0000, Nux! wrote:
> This might still be an issue
> 
> http://www.nux.ro/oldblog/archive/2014/01/Taking_KVM_volume_snapshots_with_Cloudstack_4_2_on_CentOS_6_5.html
> 
> --
> Sent from the Delta quadrant using Borg technology!
> 
> Nux!
> www.nux.ro
> 
> ----- Original Message -----
> > From: "Vladimir Melnik" <v....@uplink.ua>
> > To: "users" <us...@cloudstack.apache.org>
> > Sent: Friday, 17 February, 2017 18:53:14
> > Subject: Using CentOS-6.x on KVM-hosts - what are the threats?
> 
> > Dear colleagues,
> > 
> > I've just realized that my KVM-hosts are running CentOS-6 whilst it's
> > recommended to use CentOS-7 with the new versions of ACS. Everything
> > seems to be fine (some of these hosts are working for a few years),
> > hosts are working and things are great, but I'd like to ask a couple of
> > questions. Here they are.
> > 
> > (1) How high is the chance of the next version of ACS (4.10 or 4.11)
> > will be incompatible with CentOS-6? Should I worry about that and
> > consider upgrading to CentOS-7 immediately?
> > 
> > (2) What ACS features I'm missing because of that? I suppose that I'll
> > be disappointed if I try to limit a VM's IO-consumption, just because
> > old good QEMU-0.9 won't support it. Am I right? Are there other things
> > that are worth of upgraging to CentOS-7?
> > 
> > Thank you very much in advance for your replies!
> > 
> > --
> > V.Melnik

-- 
V.Melnik

Re: Using CentOS-6.x on KVM-hosts - what are the threats?

[Nux! <nu...@li.nux.ro>]

This might still be an issue

http://www.nux.ro/oldblog/archive/2014/01/Taking_KVM_volume_snapshots_with_Cloudstack_4_2_on_CentOS_6_5.html

--
Sent from the Delta quadrant using Borg technology!

Nux!
www.nux.ro

----- Original Message -----
> From: "Vladimir Melnik" <v....@uplink.ua>
> To: "users" <us...@cloudstack.apache.org>
> Sent: Friday, 17 February, 2017 18:53:14
> Subject: Using CentOS-6.x on KVM-hosts - what are the threats?

> Dear colleagues,
> 
> I've just realized that my KVM-hosts are running CentOS-6 whilst it's
> recommended to use CentOS-7 with the new versions of ACS. Everything
> seems to be fine (some of these hosts are working for a few years),
> hosts are working and things are great, but I'd like to ask a couple of
> questions. Here they are.
> 
> (1) How high is the chance of the next version of ACS (4.10 or 4.11)
> will be incompatible with CentOS-6? Should I worry about that and
> consider upgrading to CentOS-7 immediately?
> 
> (2) What ACS features I'm missing because of that? I suppose that I'll
> be disappointed if I try to limit a VM's IO-consumption, just because
> old good QEMU-0.9 won't support it. Am I right? Are there other things
> that are worth of upgraging to CentOS-7?
> 
> Thank you very much in advance for your replies!
> 
> --
> V.Melnik