On Mon, Jul 3, 2017 at 4:40 PM, Andrew Dent <adent(a)ctcroydon.com.au> wrote:
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.
Meaning? It does not even boot? If so, then I am afraid that you
need to follow the linked procedure, including deploying hosted-engine
again on new (or fully cleaned) storage.
Are all 3 hosts also hosted-engine hosts? And you want to keep them
this way? If so, you'll have to reinstall them.
I think, didn't try, that after you deploy a new hosted-engine host,
and restore the engine, the new engine will see your existing hosts,
but hosted-engine-ha will not work.
If you want to try and keep your VMs running, I guess your best bet
is to try to add a new non-hosted-engine host (one or more, as needed),
migrate your VMs to it (them), then remove the hosted-engine hosts and
deploy them again as described there.
However I have a backup of the hosted-engine database (do I need
anything
else).
Only database? Or a backup taken by engine-backup? You also need various
configuration files. To see the full list, in case you didn't use
engine-backup but can restore individual files, check BACKUP_PATHS inside
the script. But this is definitely not supported - you should first try
verifying by restoring on a test VM and see what happens.
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?
As I wrote above, I think it is, but hosted-engine-ha will not work.
If at all possible, I strongly suggest to try to simulate this in a
test env. Can be done using nested-kvm VMs for hosts, if you do not have
enough real hardware.
In my previous mail I just wrote I sent a pull request, not that
the site is updated already. I updated it since and it now seems
ok to me.
Best,
Kind regards
Andrew
------ Original Message ------
From: "Yedidyah Bar David" <didi(a)redhat.com>
To: "Andrew Dent" <adent(a)ctcroydon.com.au>
Cc: "users" <users(a)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(a)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(a)ctcroydon.com.au>
>> To: "users" <users(a)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_Restor...
>> 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
--
Didi