Hi James, (/cc Simon and others),
A new feature exists in upcoming ACS 4.11, Host HA:
https://cwiki.apache.org/confluence/display/CLOUDSTACK/Host+HA
You can read more about it here as well:
http://www.shapeblue.com/host-ha-for-kvm-hosts-in-cloudstack/
This feature can use a custom HA provider, with default HA provider implemented
for KVM and NFS, and uses ipmi based fencing (STONITH) of the host. The current
HA mechanism provides no such method of fencing (powering off) a host and it
depends under what circumstances the VM HA is failing (environment issues, ACS
version etc).
As Simon mentioned, we have a (host) HA provider that works with Ceph in near
future.
Regards.
________________________________
From: Simon Weller <swel...@ena.com.INVALID>
Sent: Thursday, November 2, 2017 7:27:22 PM
To: users@cloudstack.apache.org
Subject: Re: Problems with KVM HA & STONITH
James,
Ceph is a great solution and we run all of our ACS storage on Ceph. Note that it adds
another layer of complexity to your installation, so you're going need to develop some
expertise with that platform to get comfortable with how it works. Typically you don't
want to mix Ceph with your ACS hosts. We in fact deploy 3 separate Ceph Monitors, and
then scale OSDs as required on a per cluster basis in order to add additional resiliency
(So every KVM ACS cluster has it's own Ceph "POD"). We also use Ceph for S3
storage (on completely separate Ceph clusters) for some other services.
NFS is much simpler to maintain for smaller installations in my opinion. If the
IO load you're looking at isn't going to be insanely high, you could look at
building a 2 node NFS cluster using pacemaker and DRDB for data replication
between nodes. That would reduce your storage requirement to 2 fairly low power
servers (NFS is not very cpu intensive). Currently on a host failure when using
a storage other than NFS on KVM, you will not see HA occur until you take the
failed host out of the ACS cluster. This is a historical limitation because ACS
could not confirm the host had been fenced correctly, so to avoid potential
data corruption (due to 2 hosts mounting the same storage), it doesn't do
anything until the operator intervenes. As of ACS 4.10, IPMI based fencing is
now supported on NFS and we're planning on developing similar support for Ceph.
Since you're an school district, I'm more than happy to jump on the phone with
you to talk you through these options if you'd like.
- Si
________________________________
From: McClune, James <mcclu...@norwalktruckers.net>
Sent: Thursday, November 2, 2017 8:28 AM
To: users@cloudstack.apache.org
Subject: Re: Problems with KVM HA & STONITH
Hi Simon,
Thanks for getting back to me. I created one single NFS share and added it
as primary storage. I think I better understand how the storage works, with
ACS.
I was able to get HA working with one NFS storage, which is good. However,
is there a way to incorporate multiple NFS storage pools and still have the
HA functionality? I think something like GlusterFS or Ceph (like Ivan and
Dag described) will work better.
Thank you Simon, Ivan, and Dag for your assistance!
James
On Wed, Nov 1, 2017 at 10:10 AM, Simon Weller <swel...@ena.com.invalid>
wrote:
James,
Try just configuring a single NFS server and see if your setup works. If
you have 3 NFS shares, across all 3 hosts, i'm wondering whether ACS is
picking the one you rebooted as the storage for your VMs and when that
storage goes away (when you bounce the host), all storage for your VMs
vanishes and ACS tries to reboot your other hosts.
Normally in a simple ACS setup, you would have a separate storage server
that can serve up NFS to all hosts. If a host dies, then a VM would be
brought up on a spare hosts since all hosts have access to the same storage.
Your other option is to use local storage, but that won't provide HA.
- Si
________________________________
From: McClune, James <mcclu...@norwalktruckers.net>
Sent: Monday, October 30, 2017 2:26 PM
To: users@cloudstack.apache.org
Subject: Re: Problems with KVM HA & STONITH
Hi Dag,
Thank you for responding back. I am currently running ACS 4.9 on an Ubuntu
14.04 VM. I have the three nodes, each having about 1TB of primary storage
(NFS) and 1TB of secondary storage (NFS). I added each NFS share into ACS.
All nodes are in a cluster.
Maybe I'm not understanding the setup or misconfigured something. I'm
trying to setup an HA environment where if one node goes down, running an
HA marked VM, the VM will start on another host. When I simulate a network
disconnect or reboot of a host, all of the nodes go down (STONITH?).
I am unsure on how to setup an HA environment, if all the nodes in the
cluster go down. Any help is much appreciated!
Thanks,
James
On Mon, Oct 30, 2017 at 3:49 AM, Dag Sonstebo <dag.sonst...@shapeblue.com>
wrote:
Hi James,
I think you possibly have over-configured your KVM hosts. If you use NFS
(and no clustered file system like CLVM) then there should be no need to
configure STONITH. CloudStack takes care of your HA, so this is not
something you offload to the KVM host.
(As mentioned the only time I have played with STONITH and CloudStack was
for CLVM – and I eventually found it not fit for purpose, too unstable
and
causing too many issues like you describe. Note this was for block
storage
though – not NFS).
Regards,
Dag Sonstebo
Cloud Architect
ShapeBlue
On 28/10/2017, 03:40, "Ivan Kudryavtsev" <kudryavtsev...@bw-sw.com>
wrote:
Hi. If the node losts nfs host it reboots (acs agent behaviour). If
you
really have 3 storages, you'll go clusterwide reboot everytime your
host is
down.
28 окт. 2017 г. 3:02 пользователь "Simon Weller"
<swel...@ena.com.invalid>
написал:
> Hi James,
>
>
> Can you elaborate a bit further on the storage? You say you're
running NFS
> on all 3 nodes, can you explain how it is setup?
>
> Also, what version of ACS are you running?
>
>
> - Si
>
>
>
>
> ________________________________
> From: McClune, James <mcclu...@norwalktruckers.net>
> Sent: Friday, October 27, 2017 2:21 PM
> To: users@cloudstack.apache.org
> Subject: Problems with KVM HA & STONITH
>
> Hello Apache CloudStack Community,
>
> My setup consists of the following:
>
> - Three nodes (NODE1, NODE2, and NODE3)
> NODE1 is running Ubuntu 16.04.3, NODE2 is running Ubuntu 16.04.3,
and NODE3
> is running Ubuntu 14.04.5.
> - Management Server (running on separate VM, not in cluster)
>
> The three nodes use KVM as the hypervisor. I also configured
primary
and
> secondary storage on all three of the nodes. I'm using NFS for the
primary
> & secondary storage. VM operations work great. Live migration works
great.
>
> However, when a host goes down, the HA functionality does not work
at all.
> Instead of spinning up the VM on another available host, the down
host
> seems to trigger STONITH. When STONITH happens, all hosts in the
cluster go
> down. This not only causes no HA, but also downs perfectly good
VM's. I
> have read countless articles and documentation related to this
issue. I
> still cannot find a viable solution for this issue. I really want
to
use
> Apache CloudStack, but cannot implement this in production when
STONITH
> happens.
>
> I think I have something misconfigured. I thought I would reach out
to the
> CloudStack community and ask for some friendly assistance.
>
> If there is anything (system-wise) you request in order to further
> troubleshoot this issue, please let me know and I'll send. I
appreciate any
> help in this issue!
>
> --
>
> Thanks,
>
> James
>
dag.sonst...@shapeblue.com
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]<
http://www.shapeblue.com/>
[http://www.shapeblue.com/wp-content/uploads/2017/06/logo.png]<http://www.shapeblue.com/>
Shapeblue - The CloudStack Company<http://www.shapeblue.com/>
www.shapeblue.com<http://www.shapeblue.com>
Rapid deployment framework for Apache CloudStack IaaS Clouds. CSForge is a
framework developed by ShapeBlue to deliver the rapid deployment of a
standardised ...
Shapeblue - The CloudStack Company<http://www.shapeblue.com/>
[http://www.shapeblue.com/wp-content/uploads/2017/06/logo.png]<http://www.shapeblue.com/>
Shapeblue - The CloudStack Company<http://www.shapeblue.com/>
www.shapeblue.com<http://www.shapeblue.com>
Rapid deployment framework for Apache CloudStack IaaS Clouds. CSForge is a
framework developed by ShapeBlue to deliver the rapid deployment of a
standardised ...
www.shapeblue.com<http://www.shapeblue.com>
[http://www.shapeblue.com/wp-content/uploads/2017/06/logo.png]<http://www.shapeblue.com/>
Shapeblue - The CloudStack Company<http://www.shapeblue.com/>
www.shapeblue.com<http://www.shapeblue.com>
Rapid deployment framework for Apache CloudStack IaaS Clouds. CSForge is a
framework developed by ShapeBlue to deliver the rapid deployment of a
standardised ...
Rapid deployment framework for Apache CloudStack IaaS Clouds. CSForge is a
framework developed by ShapeBlue to deliver the rapid deployment of a
standardised ...
53 Chandos Place, Covent Garden, London WC2N 4HSUK
@shapeblue
--
James McClune
Technical Support Specialist
Norwalk City Schools
Phone: 419-660-6590
mcclu...@norwalktruckers.net
--
James McClune
Technical Support Specialist
Norwalk City Schools
Phone: 419-660-6590
mcclu...@norwalktruckers.net
rohit.ya...@shapeblue.com
www.shapeblue.com
53 Chandos Place, Covent Garden, London WC2N 4HSUK
@shapeblue
