cloudstack-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Andrija Panic <andrija.pa...@gmail.com>
Subject Re: System VMs not migrating when host down
Date Wed, 14 Feb 2018 09:22:16 GMT
Humble opinion (until HOST HA is ready in 4.11 if not mistaken?), avoid
using HA option for VMs  - avoid setting the  "Offer HA" option on any
compute/service offerings, since we did end  up (was it ACS 4.5 or 4.8,
can't remember now) having 2 copies of SAME VM running on 2 different
hosts...imagine storage/volume corruption...this happened a few times for
us.

HOST HA looks like really a nice thing, I have not tested that yet...but
sould completely solve the problem.

On 14 February 2018 at 10:14, Paul Angus <paul.angus@shapeblue.com> wrote:

> Hi Sean,
>
> The 'problem' with VM HA in KVM is that it relies on the parent host agent
> to be connected to report that the VM is down.  We cannot assume that just
> because a host agent is disconnected, that the VMs on that host are not
> running.
>
> This is where HOST HA comes in, this feature detects loss of connection to
> the agent and then tries to determine if the VMs on that host are active
> and then attempts some corrective action.
>
>
> Kind regards,
>
> Paul Angus
>
> paul.angus@shapeblue.com
> www.shapeblue.com
> 53 Chandos Place, Covent Garden, London  WC2N 4HSUK
> @shapeblue
>
>
>
>
> -----Original Message-----
> From: Sean Lair [mailto:slair@ippathways.com]
> Sent: 13 February 2018 23:06
> To: dev@cloudstack.apache.org
> Subject: System VMs not migrating when host down
>
> Hi all,
>
> We are testing VM HA and are having a problem with our system VMs
> (secondary storage and console) not being started up on another host when a
> host fails.
>
> Shouldn't the system VMs be VM HA-enabled?  Currently they are just in an
> "Alert" agent state, but never migrate.  We are currently running 4.9.3.
>
>
> Thanks
> Sean
>



-- 

Andrija Panić

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message