9:33 p.m.
Hi users,
Good day, is it possible to configure two ovirt-engine to manage one
hypervisor? My purpose for this is what if the first ovirt-engine fails, I
still have the 2nd ovirt-engine to manage hypervisor.
is this possible? or any suggestion similar to my purpose?
TIA
Sandvik
12:53 a.m.
On Thu, Jun 16, 2016 at 5:33 AM, Sandvik Agustin
<agustinsandvik(a)gmail.com> wrote:
Hi users,
Good day, is it possible to configure two ovirt-engine to manage one
hypervisor? My purpose for this is what if the first ovirt-engine fails, I
still have the 2nd ovirt-engine to manage hypervisor.
is this possible? or any suggestion similar to my purpose?
The "normal" solution is hosted-engine, which has HA - the engine
runs in a VM, and HA daemons monitor it and the hosts, and if there
is a problem they can start it on another host.
There were discussions in the past, which you can find in the list archives,
about running two engines against a single database, and current bottom line
is that it's not supported, will not work, and iiuc will require some
significant development investment to support.
You might manage to have an active/passive solution - install an engine
on two machines, configure both to use the same remote database, but
make sure only one of them is active at any given time. Not sure if that's
considered "fully supported", but might come close.
You can find on the net docs/resources about creating a redundant
postgresql cluster.
Best,
--
Didi
1:10 a.m.
On Thu, Jun 16, 2016 at 8:53 AM, Yedidyah Bar David <didi(a)redhat.com> wrote:
On Thu, Jun 16, 2016 at 5:33 AM, Sandvik Agustin
<agustinsandvik(a)gmail.com> wrote:
> Hi users,
>
> Good day, is it possible to configure two ovirt-engine to manage one
> hypervisor? My purpose for this is what if the first ovirt-engine fails,
I
> still have the 2nd ovirt-engine to manage hypervisor.
>
> is this possible? or any suggestion similar to my purpose?
The "normal" solution is hosted-engine, which has HA - the engine
runs in a VM, and HA daemons monitor it and the hosts, and if there
is a problem they can start it on another host.
There were discussions in the past, which you can find in the list
archives,
about running two engines against a single database, and current bottom
line
is that it's not supported, will not work, and iiuc will require some
significant development investment to support.
You might manage to have an active/passive solution - install an engine
on two machines, configure both to use the same remote database, but
make sure only one of them is active at any given time. Not sure if that's
considered "fully supported", but might come close.
That's not enough - they need to share the same set of certificates...
Y.
You can find on the net docs/resources about creating a redundant
postgresql cluster.
Best,
--
Didi
_______________________________________________
Users mailing list
Users(a)ovirt.org
http://lists.ovirt.org/mailman/listinfo/users
1:29 a.m.
On Thu, Jun 16, 2016 at 9:10 AM, Yaniv Kaul <ykaul(a)redhat.com> wrote:
On Thu, Jun 16, 2016 at 8:53 AM, Yedidyah Bar David <didi(a)redhat.com> wrote:
>
> On Thu, Jun 16, 2016 at 5:33 AM, Sandvik Agustin
> <agustinsandvik(a)gmail.com> wrote:
> > Hi users,
> >
> > Good day, is it possible to configure two ovirt-engine to manage one
> > hypervisor? My purpose for this is what if the first ovirt-engine fails,
> > I
> > still have the 2nd ovirt-engine to manage hypervisor.
> >
> > is this possible? or any suggestion similar to my purpose?
>
> The "normal" solution is hosted-engine, which has HA - the engine
> runs in a VM, and HA daemons monitor it and the hosts, and if there
> is a problem they can start it on another host.
>
> There were discussions in the past, which you can find in the list
> archives,
> about running two engines against a single database, and current bottom
> line
> is that it's not supported, will not work, and iiuc will require some
> significant development investment to support.
>
> You might manage to have an active/passive solution - install an engine
> on two machines, configure both to use the same remote database, but
> make sure only one of them is active at any given time. Not sure if that's
> considered "fully supported", but might come close.
That's not enough - they need to share the same set of certificates...
Best is to simply clone the machine after initial setup then change
what's needed, or backup/restore only files (engine-backup --mode=backup
--scope=files).
Didn't check, but I do not think they actually need all the certs of
all hosts - that is, that it's not mandatory to keep /etc/pki synced
between them after initial setup. Didn't try that myself.
Y.
>
>
> You can find on the net docs/resources about creating a redundant
> postgresql cluster.
>
> Best,
> --
> Didi
> _______________________________________________
> Users mailing list
> Users(a)ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
--
Didi
1:51 a.m.
maybe this engine-backup will work, i'll give this a try.
Thanks :)
Sandvik
On Thu, Jun 16, 2016 at 2:29 PM, Yedidyah Bar David <didi(a)redhat.com> wrote:
On Thu, Jun 16, 2016 at 9:10 AM, Yaniv Kaul <ykaul(a)redhat.com>
wrote:
>
>
> On Thu, Jun 16, 2016 at 8:53 AM, Yedidyah Bar David <didi(a)redhat.com>
wrote:
>>
>> On Thu, Jun 16, 2016 at 5:33 AM, Sandvik Agustin
>> <agustinsandvik(a)gmail.com> wrote:
>> > Hi users,
>> >
>> > Good day, is it possible to configure two ovirt-engine to manage one
>> > hypervisor? My purpose for this is what if the first ovirt-engine
fails,
>> > I
>> > still have the 2nd ovirt-engine to manage hypervisor.
>> >
>> > is this possible? or any suggestion similar to my purpose?
>>
>> The "normal" solution is hosted-engine, which has HA - the engine
>> runs in a VM, and HA daemons monitor it and the hosts, and if there
>> is a problem they can start it on another host.
>>
>> There were discussions in the past, which you can find in the list
>> archives,
>> about running two engines against a single database, and current bottom
>> line
>> is that it's not supported, will not work, and iiuc will require some
>> significant development investment to support.
>>
>> You might manage to have an active/passive solution - install an engine
>> on two machines, configure both to use the same remote database, but
>> make sure only one of them is active at any given time. Not sure if
that's
>> considered "fully supported", but might come close.
>
>
> That's not enough - they need to share the same set of certificates...
Best is to simply clone the machine after initial setup then change
what's needed, or backup/restore only files (engine-backup --mode=backup
--scope=files).
Didn't check, but I do not think they actually need all the certs of
all hosts - that is, that it's not mandatory to keep /etc/pki synced
between them after initial setup. Didn't try that myself.
> Y.
>
>>
>>
>> You can find on the net docs/resources about creating a redundant
>> postgresql cluster.
>>
>> Best,
>> --
>> Didi
>> _______________________________________________
>> Users mailing list
>> Users(a)ovirt.org
>> http://lists.ovirt.org/mailman/listinfo/users
>
>
--
Didi
2:07 a.m.
On Thu, Jun 16, 2016 at 9:29 AM, Yedidyah Bar David <didi(a)redhat.com> wrote:
On Thu, Jun 16, 2016 at 9:10 AM, Yaniv Kaul <ykaul(a)redhat.com>
wrote:
>
>
> On Thu, Jun 16, 2016 at 8:53 AM, Yedidyah Bar David <didi(a)redhat.com>
wrote:
>>
>> On Thu, Jun 16, 2016 at 5:33 AM, Sandvik Agustin
>> <agustinsandvik(a)gmail.com> wrote:
>> > Hi users,
>> >
>> > Good day, is it possible to configure two ovirt-engine to manage one
>> > hypervisor? My purpose for this is what if the first ovirt-engine
fails,
>> > I
>> > still have the 2nd ovirt-engine to manage hypervisor.
>> >
>> > is this possible? or any suggestion similar to my purpose?
>>
>> The "normal" solution is hosted-engine, which has HA - the engine
>> runs in a VM, and HA daemons monitor it and the hosts, and if there
>> is a problem they can start it on another host.
>>
>> There were discussions in the past, which you can find in the list
>> archives,
>> about running two engines against a single database, and current bottom
>> line
>> is that it's not supported, will not work, and iiuc will require some
>> significant development investment to support.
>>
>> You might manage to have an active/passive solution - install an engine
>> on two machines, configure both to use the same remote database, but
>> make sure only one of them is active at any given time. Not sure if
that's
>> considered "fully supported", but might come close.
>
>
> That's not enough - they need to share the same set of certificates...
Best is to simply clone the machine after initial setup then change
what's needed, or backup/restore only files (engine-backup --mode=backup
--scope=files).
Didn't check, but I do not think they actually need all the certs of
all hosts - that is, that it's not mandatory to keep /etc/pki synced
between them after initial setup. Didn't try that myself.
I'm not sure what happens when you provision a host from Mgmt A, then move
to Mgmt B and provision another from it:
1. Mgmt A won't be aware of that host, from cert req perspective. May not
be such a big deal - donno.
2. Can Mgmt A provision another host? Need to ensure the certificate serial
numbers are OK, etc.
They really need to share the CA DB.
The backup-restore sounds like good approach to me.
Y.
> Y.
>
>>
>>
>> You can find on the net docs/resources about creating a redundant
>> postgresql cluster.
>>
>> Best,
>> --
>> Didi
>> _______________________________________________
>> Users mailing list
>> Users(a)ovirt.org
>> http://lists.ovirt.org/mailman/listinfo/users
>
>
--
Didi
2:13 a.m.
--Apple-Mail=_546B81EA-FA0E-4CAF-B4FE-5C1B51D7CC1D
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain;
charset=us-ascii
On 16 Jun 2016, at 09:07, Yaniv Kaul <ykaul(a)redhat.com> wrote:
=20
=20
=20
On Thu, Jun 16, 2016 at 9:29 AM, Yedidyah Bar David <didi(a)redhat.com =
<mailto:didi@redhat.com>> wrote:
On Thu, Jun 16, 2016 at 9:10 AM, Yaniv Kaul <ykaul(a)redhat.com =
<mailto:ykaul@redhat.com>> wrote:
>
>
> On Thu, Jun 16, 2016 at 8:53 AM, Yedidyah Bar David <didi(a)redhat.com =
<mailto:didi@redhat.com>> wrote:
>>
>> On Thu, Jun 16, 2016 at 5:33 AM, Sandvik Agustin
>> <agustinsandvik(a)gmail.com <mailto:agustinsandvik@gmail.com>> wrote:
>> > Hi users,
>> >
>> > Good day, is it possible to configure two ovirt-engine to manage =
one
>> > hypervisor? My purpose for this is what if the first
ovirt-engine =
fails,
>> > I
>> > still have the 2nd ovirt-engine to manage hypervisor.
>> >
>> > is this possible? or any suggestion similar to my purpose?
>>
>> The "normal" solution is hosted-engine, which has HA - the engine
>> runs in a VM, and HA daemons monitor it and the hosts, and if there
>> is a problem they can start it on another host.
>>
>> There were discussions in the past, which you can find in the list
>> archives,
>> about running two engines against a single database, and current =
bottom
>> line
>> is that it's not supported, will not work, and iiuc will require =
some
>> significant development investment to support.
>>
>> You might manage to have an active/passive solution - install an =
engine
>> on two machines, configure both to use the same remote
database, =
but
>> make sure only one of them is active at any given time. Not
sure if =
that's
>> considered "fully supported", but might come
close.
even when you make it work when cert issues are sorted out, you need to =
be very careful not to bring both engines up managing a same host, they =
will fight over it and the monitoring is going to be received only by =
one of the engines, which in turn may cause HA VMs restart and split =
brains all over the place.
>
>
> That's not enough - they need to share the same set of =
certificates...
=20
Best is to simply clone the machine after initial setup then change
what's needed, or backup/restore only files (engine-backup =
--mode=3Dbackup
--scope=3Dfiles).
=20
Didn't check, but I do not think they actually need all the certs of
all hosts - that is, that it's not mandatory to keep /etc/pki synced
between them after initial setup. Didn't try that myself.
=20
I'm not sure what happens when you provision a host from Mgmt A, then =
move to
Mgmt B and provision another from it:
1. Mgmt A won't be aware of that host, from cert req perspective.
May =
not be such a big deal - donno.
2. Can Mgmt A provision another host? Need to ensure the certificate
=
serial numbers are OK, etc.
=20
They really need to share the CA DB.
The backup-restore sounds like good approach to me.
Y.
=20
=20
> Y.
>
>>
>>
>> You can find on the net docs/resources about creating a redundant
>> postgresql cluster.
>>
>> Best,
>> --
>> Didi
>> _______________________________________________
>> Users mailing list
>> Users(a)ovirt.org <mailto:Users@ovirt.org>
>> http://lists.ovirt.org/mailman/listinfo/users =
<http://lists.ovirt.org/mailman/listinfo/users>
>
>
=20
=20
=20
--
Didi
=20
_______________________________________________
Users mailing list
Users(a)ovirt.org
http://lists.ovirt.org/mailman/listinfo/users
--Apple-Mail=_546B81EA-FA0E-4CAF-B4FE-5C1B51D7CC1D
Content-Transfer-Encoding: 7bit
Content-Type: text/html;
charset=us-ascii
<html><head><meta http-equiv="Content-Type"
content="text/html charset=us-ascii"></head><body
style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break:
after-white-space;" class=""><br
class=""><div><blockquote type="cite"
class=""><div class="">On 16 Jun 2016, at 09:07, Yaniv Kaul
<<a href="mailto:ykaul@redhat.com"
class="">ykaul(a)redhat.com</a>&gt; wrote:</div><br
class="Apple-interchange-newline"><div class=""><div
dir="ltr" class=""><br class=""><div
class="gmail_extra"><br class=""><div
class="gmail_quote">On Thu, Jun 16, 2016 at 9:29 AM, Yedidyah Bar David
<span dir="ltr" class=""><<a
href="mailto:didi@redhat.com" target="_blank"
class="">didi(a)redhat.com</a>&gt;</span> wrote:<br
class=""><blockquote class="gmail_quote" style="margin:0 0
0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span
class="">On Thu, Jun 16, 2016 at 9:10 AM, Yaniv Kaul <<a
href="mailto:ykaul@redhat.com"
class="">ykaul(a)redhat.com</a>&gt; wrote:<br
class="">
><br class="">
><br class="">
> On Thu, Jun 16, 2016 at 8:53 AM, Yedidyah Bar David <<a
href="mailto:didi@redhat.com"
class="">didi(a)redhat.com</a>&gt; wrote:<br
class="">
>><br class="">
>> On Thu, Jun 16, 2016 at 5:33 AM, Sandvik Agustin<br
class="">
>> <<a href="mailto:agustinsandvik@gmail.com"
class="">agustinsandvik(a)gmail.com</a>&gt; wrote:<br
class="">
>> > Hi users,<br class="">
>> ><br class="">
>> > Good day, is it possible to configure two ovirt-engine to manage
one<br class="">
>> > hypervisor? My purpose for this is what if the first
ovirt-engine fails,<br class="">
>> > I<br class="">
>> > still have the 2nd ovirt-engine to manage hypervisor.<br
class="">
>> ><br class="">
>> > is this possible? or any suggestion similar to my purpose?<br
class="">
>><br class="">
>> The "normal" solution is hosted-engine, which has HA - the
engine<br class="">
>> runs in a VM, and HA daemons monitor it and the hosts, and if there<br
class="">
>> is a problem they can start it on another host.<br
class="">
>><br class="">
>> There were discussions in the past, which you can find in the list<br
class="">
>> archives,<br class="">
>> about running two engines against a single database, and current
bottom<br class="">
>> line<br class="">
>> is that it's not supported, will not work, and iiuc will require
some<br class="">
>> significant development investment to support.<br
class="">
>><br class="">
>> You might manage to have an active/passive solution - install an
engine<br class="">
>> on two machines, configure both to use the same remote database,
but<br class="">
>> make sure only one of them is active at any given time. Not sure if
that's<br class="">
>> considered "fully supported", but might come close.<br
class=""></span></blockquote></div></div></div></div></blockquote><div><br
class=""></div>even when you make it work when cert issues are sorted
out, you need to be very careful not to bring both engines up managing a same host, they
will fight over it and the monitoring is going to be received only by one of the engines,
which in turn may cause HA VMs restart and split brains all over the
place.</div><div><br class=""><blockquote
type="cite" class=""><div class=""><div
dir="ltr" class=""><div class="gmail_extra"><div
class="gmail_quote"><blockquote class="gmail_quote"
style="margin:0 0 0 .8ex;border-left:1px #ccc
solid;padding-left:1ex"><span class="">
><br class="">
><br class="">
> That's not enough - they need to share the same set of certificates...<br
class="">
<br class="">
</span>Best is to simply clone the machine after initial setup then change<br
class="">
what's needed, or backup/restore only files (engine-backup --mode=backup<br
class="">
--scope=files).<br class="">
<br class="">
Didn't check, but I do not think they actually need all the certs of<br
class="">
all hosts - that is, that it's not mandatory to keep /etc/pki synced<br
class="">
between them after initial setup. Didn't try that myself.<br
class=""></blockquote><div class=""><br
class=""></div><div class="">I'm not sure what
happens when you provision a host from Mgmt A, then move to Mgmt B and provision another
from it:</div><div class="">1. Mgmt A won't be aware of that
host, from cert req perspective. May not be such a big deal -
donno.</div></div></div></div></div></blockquote></div><div><blockquote
type="cite" class=""><div class=""><div
dir="ltr" class=""><div class="gmail_extra"><div
class="gmail_quote"><div class="">2. Can Mgmt A provision
another host? Need to ensure the certificate serial numbers are OK,
etc.</div><div class=""><br
class=""></div><div class="">They really need to share
the CA DB.</div><div class="">The backup-restore sounds like good
approach to me.</div><div class="">Y.</div><div
class=""><br class=""></div><blockquote
class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc
solid;padding-left:1ex">
<div class="HOEnZb"><div class="h5"><br
class="">
> Y.<br class="">
><br class="">
>><br class="">
>><br class="">
>> You can find on the net docs/resources about creating a redundant<br
class="">
>> postgresql cluster.<br class="">
>><br class="">
>> Best,<br class="">
>> --<br class="">
>> Didi<br class="">
>> _______________________________________________<br
class="">
>> Users mailing list<br class="">
>> <a href="mailto:Users@ovirt.org"
class="">Users(a)ovirt.org</a><br class="">
>> <a href="http://lists.ovirt.org/mailman/listinfo/users"
rel="noreferrer" target="_blank"
class="">http://lists.ovirt.org/mailman/listinfo/users</a...
class="">
><br class="">
><br class="">
<br class="">
<br class="">
<br class="">
</div></div><span class="HOEnZb"><font
color="#888888" class="">--<br class="">
Didi<br class="">
</font></span></blockquote></div><br
class=""></div></div>
_______________________________________________<br class="">Users mailing
list<br class=""><a href="mailto:Users@ovirt.org"
class="">Users(a)ovirt.org</a><br
class="">http://lists.ovirt.org/mailman/listinfo/users<br
class=""></div></blockquote></div><br
class=""></body></html>
--Apple-Mail=_546B81EA-FA0E-4CAF-B4FE-5C1B51D7CC1D--
2:23 a.m.
Yes, bringing up both engines can cause disaster, iv'e tried that once to
bring up both of my engines and my engine1 droped the connection coz host1
was called by the engine2, host1 don't know how to talk two engines at the
same time, I tried this with a running vm on the host1 just to test if what
will happen to that vm and the results are "the vm is lost in the space".
On Thu, Jun 16, 2016 at 3:13 PM, Michal Skrivanek <
michal.skrivanek(a)redhat.com> wrote:
On 16 Jun 2016, at 09:07, Yaniv Kaul <ykaul(a)redhat.com> wrote:
On Thu, Jun 16, 2016 at 9:29 AM, Yedidyah Bar David <didi(a)redhat.com>
wrote:
> On Thu, Jun 16, 2016 at 9:10 AM, Yaniv Kaul <ykaul(a)redhat.com> wrote:
> >
> >
> > On Thu, Jun 16, 2016 at 8:53 AM, Yedidyah Bar David <didi(a)redhat.com>
> wrote:
> >>
> >> On Thu, Jun 16, 2016 at 5:33 AM, Sandvik Agustin
> >> <agustinsandvik(a)gmail.com> wrote:
> >> > Hi users,
> >> >
> >> > Good day, is it possible to configure two ovirt-engine to manage one
> >> > hypervisor? My purpose for this is what if the first ovirt-engine
> fails,
> >> > I
> >> > still have the 2nd ovirt-engine to manage hypervisor.
> >> >
> >> > is this possible? or any suggestion similar to my purpose?
> >>
> >> The "normal" solution is hosted-engine, which has HA - the engine
> >> runs in a VM, and HA daemons monitor it and the hosts, and if there
> >> is a problem they can start it on another host.
> >>
> >> There were discussions in the past, which you can find in the list
> >> archives,
> >> about running two engines against a single database, and current bottom
> >> line
> >> is that it's not supported, will not work, and iiuc will require some
> >> significant development investment to support.
> >>
> >> You might manage to have an active/passive solution - install an engine
> >> on two machines, configure both to use the same remote database, but
> >> make sure only one of them is active at any given time. Not sure if
> that's
> >> considered "fully supported", but might come close.
>
even when you make it work when cert issues are sorted out, you need to be
very careful not to bring both engines up managing a same host, they will
fight over it and the monitoring is going to be received only by one of the
engines, which in turn may cause HA VMs restart and split brains all over
the place.
>
> >
> > That's not enough - they need to share the same set of certificates...
>
> Best is to simply clone the machine after initial setup then change
> what's needed, or backup/restore only files (engine-backup --mode=backup
> --scope=files).
>
> Didn't check, but I do not think they actually need all the certs of
> all hosts - that is, that it's not mandatory to keep /etc/pki synced
> between them after initial setup. Didn't try that myself.
>
I'm not sure what happens when you provision a host from Mgmt A, then move
to Mgmt B and provision another from it:
1. Mgmt A won't be aware of that host, from cert req perspective. May not
be such a big deal - donno.
2. Can Mgmt A provision another host? Need to ensure the certificate
serial numbers are OK, etc.
They really need to share the CA DB.
The backup-restore sounds like good approach to me.
Y.
> > Y.
> >
> >>
> >>
> >> You can find on the net docs/resources about creating a redundant
> >> postgresql cluster.
> >>
> >> Best,
> >> --
> >> Didi
> >> _______________________________________________
> >> Users mailing list
> >> Users(a)ovirt.org
> >> http://lists.ovirt.org/mailman/listinfo/users
> >
> >
>
>
>
> --
> Didi
>
_______________________________________________
Users mailing list
Users(a)ovirt.org
http://lists.ovirt.org/mailman/listinfo/users
3:17 a.m.
On Thu, Jun 16, 2016 at 10:13 AM, Michal Skrivanek
<michal.skrivanek(a)redhat.com> wrote:
On 16 Jun 2016, at 09:07, Yaniv Kaul <ykaul(a)redhat.com> wrote:
On Thu, Jun 16, 2016 at 9:29 AM, Yedidyah Bar David <didi(a)redhat.com> wrote:
>
> On Thu, Jun 16, 2016 at 9:10 AM, Yaniv Kaul <ykaul(a)redhat.com> wrote:
> >
> >
> > On Thu, Jun 16, 2016 at 8:53 AM, Yedidyah Bar David <didi(a)redhat.com>
> > wrote:
> >>
> >> On Thu, Jun 16, 2016 at 5:33 AM, Sandvik Agustin
> >> <agustinsandvik(a)gmail.com> wrote:
> >> > Hi users,
> >> >
> >> > Good day, is it possible to configure two ovirt-engine to manage one
> >> > hypervisor? My purpose for this is what if the first ovirt-engine
> >> > fails,
> >> > I
> >> > still have the 2nd ovirt-engine to manage hypervisor.
> >> >
> >> > is this possible? or any suggestion similar to my purpose?
> >>
> >> The "normal" solution is hosted-engine, which has HA - the engine
> >> runs in a VM, and HA daemons monitor it and the hosts, and if there
> >> is a problem they can start it on another host.
> >>
> >> There were discussions in the past, which you can find in the list
> >> archives,
> >> about running two engines against a single database, and current bottom
> >> line
> >> is that it's not supported, will not work, and iiuc will require some
> >> significant development investment to support.
> >>
> >> You might manage to have an active/passive solution - install an engine
> >> on two machines, configure both to use the same remote database, but
> >> make sure only one of them is active at any given time. Not sure if
> >> that's
> >> considered "fully supported", but might come close.
even when you make it work when cert issues are sorted out, you need to be
very careful not to bring both engines up managing a same host, they will
fight over it and the monitoring is going to be received only by one of the
engines, which in turn may cause HA VMs restart and split brains all over
the place.
And, IIRC from previous discussions, also internal caches etc.
But this is not something specific to ovirt-engine - many services
have similar restrictions, and common clustering tools allow handling
them.
> >
> >
> > That's not enough - they need to share the same set of certificates...
>
> Best is to simply clone the machine after initial setup then change
> what's needed, or backup/restore only files (engine-backup --mode=backup
> --scope=files).
>
> Didn't check, but I do not think they actually need all the certs of
> all hosts - that is, that it's not mandatory to keep /etc/pki synced
> between them after initial setup. Didn't try that myself.
I'm not sure what happens when you provision a host from Mgmt A, then move
to Mgmt B and provision another from it:
1. Mgmt A won't be aware of that host, from cert req perspective. May not be
such a big deal - donno.
2. Can Mgmt A provision another host? Need to ensure the certificate serial
numbers are OK, etc.
They really need to share the CA DB.
Even keeping /etc/pki synced, or mounted from each one before
starting the engine and umounting when stopping, should not be
too hard.
The backup-restore sounds like good approach to me.
Y.
>
> > Y.
> >
> >>
> >>
> >> You can find on the net docs/resources about creating a redundant
> >> postgresql cluster.
> >>
> >> Best,
> >> --
> >> Didi
> >> _______________________________________________
> >> Users mailing list
> >> Users(a)ovirt.org
> >> http://lists.ovirt.org/mailman/listinfo/users
> >
> >
>
>
>
> --
> Didi
_______________________________________________
Users mailing list
Users(a)ovirt.org
http://lists.ovirt.org/mailman/listinfo/users
--
Didi
3:19 a.m.
You had to test it with 3.5. In 3.6+ we support more clients so the
connection drop would be not the issue anymore.
There are number of logical issues that would make your env not usable
like Michal mentioned. Assuming at least two hosts it could happen
that different hosts would become SPM for different engines.
Engine is not designed to coexist with other engine and I suggest to
not take this path. You may want to consider using hosted engine or
use standalone engine which is able to recover after a crash.
On Thu, Jun 16, 2016 at 10:17 AM, Yedidyah Bar David <didi(a)redhat.com> wrote:
On Thu, Jun 16, 2016 at 10:13 AM, Michal Skrivanek
<michal.skrivanek(a)redhat.com> wrote:
>
> On 16 Jun 2016, at 09:07, Yaniv Kaul <ykaul(a)redhat.com> wrote:
>
>
>
> On Thu, Jun 16, 2016 at 9:29 AM, Yedidyah Bar David <didi(a)redhat.com> wrote:
>>
>> On Thu, Jun 16, 2016 at 9:10 AM, Yaniv Kaul <ykaul(a)redhat.com> wrote:
>> >
>> >
>> > On Thu, Jun 16, 2016 at 8:53 AM, Yedidyah Bar David <didi(a)redhat.com>
>> > wrote:
>> >>
>> >> On Thu, Jun 16, 2016 at 5:33 AM, Sandvik Agustin
>> >> <agustinsandvik(a)gmail.com> wrote:
>> >> > Hi users,
>> >> >
>> >> > Good day, is it possible to configure two ovirt-engine to manage
one
>> >> > hypervisor? My purpose for this is what if the first ovirt-engine
>> >> > fails,
>> >> > I
>> >> > still have the 2nd ovirt-engine to manage hypervisor.
>> >> >
>> >> > is this possible? or any suggestion similar to my purpose?
>> >>
>> >> The "normal" solution is hosted-engine, which has HA - the
engine
>> >> runs in a VM, and HA daemons monitor it and the hosts, and if there
>> >> is a problem they can start it on another host.
>> >>
>> >> There were discussions in the past, which you can find in the list
>> >> archives,
>> >> about running two engines against a single database, and current bottom
>> >> line
>> >> is that it's not supported, will not work, and iiuc will require
some
>> >> significant development investment to support.
>> >>
>> >> You might manage to have an active/passive solution - install an engine
>> >> on two machines, configure both to use the same remote database, but
>> >> make sure only one of them is active at any given time. Not sure if
>> >> that's
>> >> considered "fully supported", but might come close.
>
>
> even when you make it work when cert issues are sorted out, you need to be
> very careful not to bring both engines up managing a same host, they will
> fight over it and the monitoring is going to be received only by one of the
> engines, which in turn may cause HA VMs restart and split brains all over
> the place.
And, IIRC from previous discussions, also internal caches etc.
But this is not something specific to ovirt-engine - many services
have similar restrictions, and common clustering tools allow handling
them.
>
>> >
>> >
>> > That's not enough - they need to share the same set of certificates...
>>
>> Best is to simply clone the machine after initial setup then change
>> what's needed, or backup/restore only files (engine-backup --mode=backup
>> --scope=files).
>>
>> Didn't check, but I do not think they actually need all the certs of
>> all hosts - that is, that it's not mandatory to keep /etc/pki synced
>> between them after initial setup. Didn't try that myself.
>
>
> I'm not sure what happens when you provision a host from Mgmt A, then move
> to Mgmt B and provision another from it:
> 1. Mgmt A won't be aware of that host, from cert req perspective. May not be
> such a big deal - donno.
>
> 2. Can Mgmt A provision another host? Need to ensure the certificate serial
> numbers are OK, etc.
>
> They really need to share the CA DB.
Even keeping /etc/pki synced, or mounted from each one before
starting the engine and umounting when stopping, should not be
too hard.
> The backup-restore sounds like good approach to me.
> Y.
>
>>
>> > Y.
>> >
>> >>
>> >>
>> >> You can find on the net docs/resources about creating a redundant
>> >> postgresql cluster.
>> >>
>> >> Best,
>> >> --
>> >> Didi
>> >> _______________________________________________
>> >> Users mailing list
>> >> Users(a)ovirt.org
>> >> http://lists.ovirt.org/mailman/listinfo/users
>> >
>> >
>>
>>
>>
>> --
>> Didi
>
>
> _______________________________________________
> Users mailing list
> Users(a)ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
>
>
--
Didi
_______________________________________________
Users mailing list
Users(a)ovirt.org
http://lists.ovirt.org/mailman/listinfo/users
3:32 a.m.
On Thu, Jun 16, 2016 at 11:19 AM, Piotr Kliczewski
<piotr.kliczewski(a)gmail.com> wrote:
You had to test it with 3.5. In 3.6+ we support more clients so the
connection drop would be not the issue anymore.
There are number of logical issues that would make your env not usable
like Michal mentioned. Assuming at least two hosts it could happen
that different hosts would become SPM for different engines.
Engine is not designed to coexist with other engine and I suggest to
not take this path.
Even two engines that something external (clustering tool) prevents them
from running in parallel? With same database?
You may want to consider using hosted engine or
use standalone engine which is able to recover after a crash.
Already mentioned, but I understand people that want to explore
other options. In principle it might provide faster reaction to
failure, depending on implementation.
On Thu, Jun 16, 2016 at 10:17 AM, Yedidyah Bar David <didi(a)redhat.com> wrote:
> On Thu, Jun 16, 2016 at 10:13 AM, Michal Skrivanek
> <michal.skrivanek(a)redhat.com> wrote:
>>
>> On 16 Jun 2016, at 09:07, Yaniv Kaul <ykaul(a)redhat.com> wrote:
>>
>>
>>
>> On Thu, Jun 16, 2016 at 9:29 AM, Yedidyah Bar David <didi(a)redhat.com>
wrote:
>>>
>>> On Thu, Jun 16, 2016 at 9:10 AM, Yaniv Kaul <ykaul(a)redhat.com> wrote:
>>> >
>>> >
>>> > On Thu, Jun 16, 2016 at 8:53 AM, Yedidyah Bar David
<didi(a)redhat.com>
>>> > wrote:
>>> >>
>>> >> On Thu, Jun 16, 2016 at 5:33 AM, Sandvik Agustin
>>> >> <agustinsandvik(a)gmail.com> wrote:
>>> >> > Hi users,
>>> >> >
>>> >> > Good day, is it possible to configure two ovirt-engine to
manage one
>>> >> > hypervisor? My purpose for this is what if the first
ovirt-engine
>>> >> > fails,
>>> >> > I
>>> >> > still have the 2nd ovirt-engine to manage hypervisor.
>>> >> >
>>> >> > is this possible? or any suggestion similar to my purpose?
>>> >>
>>> >> The "normal" solution is hosted-engine, which has HA - the
engine
>>> >> runs in a VM, and HA daemons monitor it and the hosts, and if there
>>> >> is a problem they can start it on another host.
>>> >>
>>> >> There were discussions in the past, which you can find in the list
>>> >> archives,
>>> >> about running two engines against a single database, and current
bottom
>>> >> line
>>> >> is that it's not supported, will not work, and iiuc will require
some
>>> >> significant development investment to support.
>>> >>
>>> >> You might manage to have an active/passive solution - install an
engine
>>> >> on two machines, configure both to use the same remote database,
but
>>> >> make sure only one of them is active at any given time. Not sure if
>>> >> that's
>>> >> considered "fully supported", but might come close.
>>
>>
>> even when you make it work when cert issues are sorted out, you need to be
>> very careful not to bring both engines up managing a same host, they will
>> fight over it and the monitoring is going to be received only by one of the
>> engines, which in turn may cause HA VMs restart and split brains all over
>> the place.
>
> And, IIRC from previous discussions, also internal caches etc.
>
> But this is not something specific to ovirt-engine - many services
> have similar restrictions, and common clustering tools allow handling
> them.
>
>>
>>> >
>>> >
>>> > That's not enough - they need to share the same set of
certificates...
>>>
>>> Best is to simply clone the machine after initial setup then change
>>> what's needed, or backup/restore only files (engine-backup --mode=backup
>>> --scope=files).
>>>
>>> Didn't check, but I do not think they actually need all the certs of
>>> all hosts - that is, that it's not mandatory to keep /etc/pki synced
>>> between them after initial setup. Didn't try that myself.
>>
>>
>> I'm not sure what happens when you provision a host from Mgmt A, then move
>> to Mgmt B and provision another from it:
>> 1. Mgmt A won't be aware of that host, from cert req perspective. May not be
>> such a big deal - donno.
>>
>> 2. Can Mgmt A provision another host? Need to ensure the certificate serial
>> numbers are OK, etc.
>>
>> They really need to share the CA DB.
>
> Even keeping /etc/pki synced, or mounted from each one before
> starting the engine and umounting when stopping, should not be
> too hard.
>
>> The backup-restore sounds like good approach to me.
>> Y.
>>
>>>
>>> > Y.
>>> >
>>> >>
>>> >>
>>> >> You can find on the net docs/resources about creating a redundant
>>> >> postgresql cluster.
>>> >>
>>> >> Best,
>>> >> --
>>> >> Didi
>>> >> _______________________________________________
>>> >> Users mailing list
>>> >> Users(a)ovirt.org
>>> >> http://lists.ovirt.org/mailman/listinfo/users
>>> >
>>> >
>>>
>>>
>>>
>>> --
>>> Didi
>>
>>
>> _______________________________________________
>> Users mailing list
>> Users(a)ovirt.org
>> http://lists.ovirt.org/mailman/listinfo/users
>>
>>
>
>
>
> --
> Didi
> _______________________________________________
> Users mailing list
> Users(a)ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
--
Didi
2870
days inactive
2870
days old
10 comments
5 participants
participants (5)
-
Michal Skrivanek -
Piotr Kliczewski -
Sandvik Agustin -
Yaniv Kaul -
Yedidyah Bar David