[ovirt-users] Recovering hosted-engine

Mon Jul 3 14:16:12 UTC 2017

Hi andrew,

This is my personal experience on recovery.

Yes you can recover the hosted-engine from a backup (almost every action you did on on oVirt after backup will have to be manually reproduced)
This can be tricky depending on your conditions (and there are some subtleties which can have significant impact later on)

- Do you have still SSH access to engine ?
- If so, do you trust engine VM OS, or should you reinstall it ?

If both questions are positive, then you just need to do a engine restore as explained here :

http://www.ovirt.org/documentation/admin-guide/chap-Backups_and_Migration/

cordialement, regards, 

	Nelson LAMEIRAS 
Ingénieur Systèmes et Réseaux / Systems and Networks engineer 
Tel: +33 5 32 09 09 70 
nelson.lameiras at lyra-network.com 

www.lyra-network.com | www.payzen.eu 

Lyra Network, 109 rue de l'innovation, 31670 Labège, FRANCE

----- Original Message -----
From: "Andrew Dent" <adent at ctcroydon.com.au>
To: "Yedidyah Bar David" <didi at redhat.com>, "users" <users at ovirt.org>
Sent: Monday, July 3, 2017 3:40:38 PM
Subject: Re: [ovirt-users] Recovering hosted-engine

Hi Didi

Fair enough.
If I'm in this situation.....
I have 3 hosts with 6 production VMs.
The hosted-engine VM is completely toast and not recoverable.
However I have a backup of the hosted-engine database (do I need 
anything else).

Is it possible to build a new VM, import the backup of the previous 
hosted-engine database and reconnect the storage domains and VMs in 
their running state without any VMs experiencing an outage?

The URL  
http://www.ovirt.org/documentation/self-hosted/chap-Backing_up_and_Restoring_an_EL-Based_Self-Hosted_Environment/
looks to be longer now.
I'll review, test and see if this will give me what I'm looking for.

The broken link still seems to be broken.
When I click the link, the browser ends up at this
http://www.ovirt.org/documentation/self-hosted/chap-Backing_up_and_Restoring_an_EL-Based_Self-Hosted_Environment/chap-Installing_Additional_Hosts_to_a_Self-Hosted_Environment#documentation%20self%20hosted%20chap%20Backing%20up%20and%20Restoring%20an%20EL%20Based%20Self%20Hosted%20Environment%20chap%20Installing%20Additional%20Hosts%20to%20a%20Self%20Hosted%20Environment

But I suspect it should be
http://www.ovirt.org/documentation/self-hosted/chap-Installing_Additional_Hosts_to_a_Self-Hosted_Environment/

Kind regards

Andrew

------ Original Message ------
From: "Yedidyah Bar David" <didi at redhat.com>
To: "Andrew Dent" <adent at ctcroydon.com.au>
Cc: "users" <users at ovirt.org>
Sent: 3/07/2017 11:12:05 PM
Subject: Re: [ovirt-users] Recovering hosted-engine

>On Mon, Jul 3, 2017 at 3:46 PM, Andrew Dent <adent at ctcroydon.com.au> 
>wrote:
>>  Has anyone successfully completed a hosted-engine recovery on a 
>>multiple
>>  host setup with production VMs?
>
>I'd like to clarify that "recovery" can span a large spectrum of
>flows, from a trivial "I did some change to the engine database
>that broke stuff and I want to restore a backup I took prior to
>this change" to a full system restoration including purchasing
>and deploying new (perhaps different) hosts/network/storage
>hardware, including many other flows in between.
>
>So when you plan for recovery, you should define very well what
>flows you plan to handle, and how you handle each.
>
>The linked procedure correctly says it's "providing an example".
>
>>
>>  Kind regards
>>
>>
>>  Andrew
>>
>>
>>
>>  ------ Original Message ------
>>  From: "Andrew Dent" <adent at ctcroydon.com.au>
>>  To: "users" <users at ovirt.org>
>>  Sent: 2/07/2017 2:22:16 PM
>>  Subject: [ovirt-users] Recovering hosted-engine
>>
>>  Hi
>>
>>  A couple of questions about hosted-engine recovery.
>>  Part way through this URL, in the section "Workflow for Restoring the
>>  Self-Hosted Engine Environment"
>>  
>>http://www.ovirt.org/documentation/self-hosted/chap-Backing_up_and_Restoring_an_EL-Based_Self-Hosted_Environment/
>>  it looks like once the hosted-engine is recovered on Host 1, the VMs 
>>on Host
>>  2 and 3 will be running, but not accessible to the recovered Hosted 
>>Engine.
>>  Is that correct?
>
>I am pretty certain that the procedure assumed that all hosts need 
>restoration,
>not that some are still up-and-running.
>
>>  If so, how to you remove host 2 and host 3 from the environment, then 
>>add
>>  back in again while keeping the VMs running?
>
>That's a good question.
>
>Please try to describe the exact flow you have in mind. What's broken 
>and
>needs restoration, and how do you plan to do that?
>
>>
>>  Host 2 and Host 3 are not recoverable in their current state. These 
>>hosts
>>  need to be removed from the environment, and then added again to the
>>  environment using the hosted-engine deployment script. For more 
>>information
>>  on these actions, see the Removing Non-Operational Hosts from a 
>>Restored
>>  Self-Hosted Engine Environment section below and Chapter 7: 
>>Installing
>>  Additional Hosts to a Self-Hosted Environment.
>>
>>  BTW: The link referring to chapter 7 is broken.
>
>You are right. The link in the bottom of the page seems working.
>Now pushed [1] to fix. Thanks for the report!
>
>[1]
>
>Best,
>--
>Didi

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