Re: [ovirt-users] Maximum time node can be offline.

[Thomas Letherby]

Thanks Yaniv, that looks like a perfect starting point!

Thomas

On Sun, Feb 11, 2018, 1:36 AM Yaniv Kaul  wrote:

> On Sat, Feb 10, 2018 at 5:47 PM, Thomas Letherby 
> wrote:
>
>> That's exactly what I needed to know, thanks all.
>>
>> I'll schedule a script for the nodes to reboot and patch once every week
>> or two and then I can let it run without me needing to worry about it.
>>
>
> An example on how to check for updates is available @
> https://github.com/oVirt/ovirt-engine-sdk/blob/master/sdk/examples/upgrade_host.py
> Y.
>
>
>> Thomas
>>
>> On Fri, Feb 9, 2018, 2:26 AM Martin Sivak  wrote:
>>
>>> Hi,
>>>
>>> the hosts are almost stateless and we set up most of what is needed
>>> during activation. Hosted engine has some configuration stored
>>> locally, but that is just the path to the storage domain.
>>>
>>> I think you should be fine unless you change the network topology
>>> significantly. I would also install security updates once in while.
>>>
>>> We can even shut down the hosts for you when you configure two cluster
>>> scheduling properties: EnableAutomaticPM and HostsInReserve.
>>> HostsInReserve should be at least 1 though. It behaves like this, as
>>> long as the reserve host is empty, we shut down all the other empty
>>> hosts. And we boot another host once a VM does not fit on other used
>>> hosts and is places on the running reserve host. That would save you
>>> the power of just one host, but it would still be highly available (if
>>> hosted engine and storage allows that too).
>>>
>>> Bear in mind that single host cluster is not highly available at all.
>>>
>>> Best regards
>>>
>>> Martin Sivak
>>>
>>> On Fri, Feb 9, 2018 at 8:25 AM, Gianluca Cecchi
>>>  wrote:
>>> > On Fri, Feb 9, 2018 at 2:30 AM, Thomas Letherby 
>>> wrote:
>>> >>
>>> >> Thanks, that answers my follow up question! :)
>>> >>
>>> >> My concern is that I could have a host off-line for a month say, is
>>> that
>>> >> going to cause any issues?
>>> >>
>>> >> Thanks,
>>> >>
>>> >> Thomas
>>> >>
>>> >
>>> > I think that if in the mean time you don't make any configuration
>>> changes
>>> > and you don't update anything, there is no reason to have problems.
>>> > In case of changes done, it could depend on what they are: are you
>>> thinking
>>> > about any particular scenario?
>>> >
>>> >
>>> > ___
>>> > Users mailing list
>>> > Users@ovirt.org
>>> > http://lists.ovirt.org/mailman/listinfo/users
>>> >
>>>
>>
>> ___
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>> Users@ovirt.org
>> http://lists.ovirt.org/mailman/listinfo/users
>>
>>
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Re: [ovirt-users] Maximum time node can be offline.

[Andrei V]

On 02/10/2018 05:47 PM, Thomas Letherby wrote:
> That's exactly what I needed to know, thanks all.
>
> I'll schedule a script for the nodes to reboot and patch once every week or
> two and then I can let it run without me needing to worry about it.

Is this shell or python script with connection to oVirt engine? My 4.2
node don't shutdown properly until I'm shutdown all VMs take it into
maintenance mode manually. Shutdown process freezes at certain point.

>
> Thomas
>
> On Fri, Feb 9, 2018, 2:26 AM Martin Sivak  wrote:
>
>> Hi,
>>
>> the hosts are almost stateless and we set up most of what is needed
>> during activation. Hosted engine has some configuration stored
>> locally, but that is just the path to the storage domain.
>>
>> I think you should be fine unless you change the network topology
>> significantly. I would also install security updates once in while.
>>
>> We can even shut down the hosts for you when you configure two cluster
>> scheduling properties: EnableAutomaticPM and HostsInReserve.
>> HostsInReserve should be at least 1 though. It behaves like this, as
>> long as the reserve host is empty, we shut down all the other empty
>> hosts. And we boot another host once a VM does not fit on other used
>> hosts and is places on the running reserve host. That would save you
>> the power of just one host, but it would still be highly available (if
>> hosted engine and storage allows that too).
>>
>> Bear in mind that single host cluster is not highly available at all.
>>
>> Best regards
>>
>> Martin Sivak
>>
>> On Fri, Feb 9, 2018 at 8:25 AM, Gianluca Cecchi
>>  wrote:
>>> On Fri, Feb 9, 2018 at 2:30 AM, Thomas Letherby 
>> wrote:
 Thanks, that answers my follow up question! :)

 My concern is that I could have a host off-line for a month say, is that
 going to cause any issues?

 Thanks,

 Thomas

>>> I think that if in the mean time you don't make any configuration changes
>>> and you don't update anything, there is no reason to have problems.
>>> In case of changes done, it could depend on what they are: are you
>> thinking
>>> about any particular scenario?
>>>
>>>
>>> ___
>>> Users mailing list
>>> Users@ovirt.org
>>> http://lists.ovirt.org/mailman/listinfo/users
>>>
>
>
> ___
> Users mailing list
> Users@ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users


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Re: [ovirt-users] Maximum time node can be offline.

[Yaniv Kaul]

On Sat, Feb 10, 2018 at 5:47 PM, Thomas Letherby  wrote:

> That's exactly what I needed to know, thanks all.
>
> I'll schedule a script for the nodes to reboot and patch once every week
> or two and then I can let it run without me needing to worry about it.
>

An example on how to check for updates is available @
https://github.com/oVirt/ovirt-engine-sdk/blob/master/sdk/examples/upgrade_host.py
Y.


> Thomas
>
> On Fri, Feb 9, 2018, 2:26 AM Martin Sivak  wrote:
>
>> Hi,
>>
>> the hosts are almost stateless and we set up most of what is needed
>> during activation. Hosted engine has some configuration stored
>> locally, but that is just the path to the storage domain.
>>
>> I think you should be fine unless you change the network topology
>> significantly. I would also install security updates once in while.
>>
>> We can even shut down the hosts for you when you configure two cluster
>> scheduling properties: EnableAutomaticPM and HostsInReserve.
>> HostsInReserve should be at least 1 though. It behaves like this, as
>> long as the reserve host is empty, we shut down all the other empty
>> hosts. And we boot another host once a VM does not fit on other used
>> hosts and is places on the running reserve host. That would save you
>> the power of just one host, but it would still be highly available (if
>> hosted engine and storage allows that too).
>>
>> Bear in mind that single host cluster is not highly available at all.
>>
>> Best regards
>>
>> Martin Sivak
>>
>> On Fri, Feb 9, 2018 at 8:25 AM, Gianluca Cecchi
>>  wrote:
>> > On Fri, Feb 9, 2018 at 2:30 AM, Thomas Letherby 
>> wrote:
>> >>
>> >> Thanks, that answers my follow up question! :)
>> >>
>> >> My concern is that I could have a host off-line for a month say, is
>> that
>> >> going to cause any issues?
>> >>
>> >> Thanks,
>> >>
>> >> Thomas
>> >>
>> >
>> > I think that if in the mean time you don't make any configuration
>> changes
>> > and you don't update anything, there is no reason to have problems.
>> > In case of changes done, it could depend on what they are: are you
>> thinking
>> > about any particular scenario?
>> >
>> >
>> > ___
>> > Users mailing list
>> > Users@ovirt.org
>> > http://lists.ovirt.org/mailman/listinfo/users
>> >
>>
>
> ___
> Users mailing list
> Users@ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
>
>
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Re: [ovirt-users] Maximum time node can be offline.

[Thomas Letherby]

That's exactly what I needed to know, thanks all.

I'll schedule a script for the nodes to reboot and patch once every week or
two and then I can let it run without me needing to worry about it.

Thomas

On Fri, Feb 9, 2018, 2:26 AM Martin Sivak  wrote:

> Hi,
>
> the hosts are almost stateless and we set up most of what is needed
> during activation. Hosted engine has some configuration stored
> locally, but that is just the path to the storage domain.
>
> I think you should be fine unless you change the network topology
> significantly. I would also install security updates once in while.
>
> We can even shut down the hosts for you when you configure two cluster
> scheduling properties: EnableAutomaticPM and HostsInReserve.
> HostsInReserve should be at least 1 though. It behaves like this, as
> long as the reserve host is empty, we shut down all the other empty
> hosts. And we boot another host once a VM does not fit on other used
> hosts and is places on the running reserve host. That would save you
> the power of just one host, but it would still be highly available (if
> hosted engine and storage allows that too).
>
> Bear in mind that single host cluster is not highly available at all.
>
> Best regards
>
> Martin Sivak
>
> On Fri, Feb 9, 2018 at 8:25 AM, Gianluca Cecchi
>  wrote:
> > On Fri, Feb 9, 2018 at 2:30 AM, Thomas Letherby 
> wrote:
> >>
> >> Thanks, that answers my follow up question! :)
> >>
> >> My concern is that I could have a host off-line for a month say, is that
> >> going to cause any issues?
> >>
> >> Thanks,
> >>
> >> Thomas
> >>
> >
> > I think that if in the mean time you don't make any configuration changes
> > and you don't update anything, there is no reason to have problems.
> > In case of changes done, it could depend on what they are: are you
> thinking
> > about any particular scenario?
> >
> >
> > ___
> > Users mailing list
> > Users@ovirt.org
> > http://lists.ovirt.org/mailman/listinfo/users
> >
>
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Re: [ovirt-users] Maximum time node can be offline.

[Martin Sivak]

Hi,

the hosts are almost stateless and we set up most of what is needed
during activation. Hosted engine has some configuration stored
locally, but that is just the path to the storage domain.

I think you should be fine unless you change the network topology
significantly. I would also install security updates once in while.

We can even shut down the hosts for you when you configure two cluster
scheduling properties: EnableAutomaticPM and HostsInReserve.
HostsInReserve should be at least 1 though. It behaves like this, as
long as the reserve host is empty, we shut down all the other empty
hosts. And we boot another host once a VM does not fit on other used
hosts and is places on the running reserve host. That would save you
the power of just one host, but it would still be highly available (if
hosted engine and storage allows that too).

Bear in mind that single host cluster is not highly available at all.

Best regards

Martin Sivak

On Fri, Feb 9, 2018 at 8:25 AM, Gianluca Cecchi
 wrote:
> On Fri, Feb 9, 2018 at 2:30 AM, Thomas Letherby  wrote:
>>
>> Thanks, that answers my follow up question! :)
>>
>> My concern is that I could have a host off-line for a month say, is that
>> going to cause any issues?
>>
>> Thanks,
>>
>> Thomas
>>
>
> I think that if in the mean time you don't make any configuration changes
> and you don't update anything, there is no reason to have problems.
> In case of changes done, it could depend on what they are: are you thinking
> about any particular scenario?
>
>
> ___
> Users mailing list
> Users@ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
>
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Re: [ovirt-users] Maximum time node can be offline.

[Gianluca Cecchi]

On Fri, Feb 9, 2018 at 2:30 AM, Thomas Letherby  wrote:

> Thanks, that answers my follow up question! :)
>
> My concern is that I could have a host off-line for a month say, is that
> going to cause any issues?
>
> Thanks,
>
> Thomas
>
>
I think that if in the mean time you don't make any configuration changes
and you don't update anything, there is no reason to have problems.
In case of changes done, it could depend on what they are: are you thinking
about any particular scenario?
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Re: [ovirt-users] Maximum time node can be offline.

[Thomas Letherby]

Thanks, that answers my follow up question! :)

My concern is that I could have a host off-line for a month say, is that
going to cause any issues?

Thanks,

Thomas

On Thu, Feb 8, 2018 at 3:12 AM Staniforth, Paul <
p.stanifo...@leedsbeckett.ac.uk> wrote:

> Hello,
>
>you should be able to use the power saving cluster scheduling
> policy.
>
>
>
> https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.2-beta/html/administration_guide/sect-Scheduling_Policies
>
>
> Regards,
>
>   Paul S.
> --
> *From:* users-boun...@ovirt.org <users-boun...@ovirt.org> on behalf of
> Thomas Letherby <xrs...@xrs444.net>
> *Sent:* 08 February 2018 05:51
> *To:* users@ovirt.org
> *Subject:* [ovirt-users] Maximum time node can be offline.
>
> Hello all,
>
> Is there a maximum length of time an Ovirt Node 4.2 based host can be
> offline in a cluster before it would have issues when powered back on?
>
> The reason I ask is in my lab I currently have a three node cluster that
> works really well, however a lot of the time I only actually need the
> resources of one host, so to save power I'd like to keep the other two
> offline until needed.
>
> I can always script them to boot once a week or so if I need to.
>
> Thanks,
>
> Thomas
> To view the terms under which this email is distributed, please go to:-
> http://disclaimer.leedsbeckett.ac.uk/disclaimer/disclaimer.html
>
>
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Re: [ovirt-users] Maximum time node can be offline.

[Staniforth, Paul]

Hello,

   you should be able to use the power saving cluster scheduling policy.


https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.2-beta/html/administration_guide/sect-Scheduling_Policies


Regards,

  Paul S.


From: users-boun...@ovirt.org <users-boun...@ovirt.org> on behalf of Thomas 
Letherby <xrs...@xrs444.net>
Sent: 08 February 2018 05:51
To: users@ovirt.org
Subject: [ovirt-users] Maximum time node can be offline.

Hello all,

Is there a maximum length of time an Ovirt Node 4.2 based host can be offline 
in a cluster before it would have issues when powered back on?

The reason I ask is in my lab I currently have a three node cluster that works 
really well, however a lot of the time I only actually need the resources of 
one host, so to save power I'd like to keep the other two offline until needed.

I can always script them to boot once a week or so if I need to.

Thanks,

Thomas
To view the terms under which this email is distributed, please go to:-
http://disclaimer.leedsbeckett.ac.uk/disclaimer/disclaimer.html
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[ovirt-users] Maximum time node can be offline.

[Thomas Letherby]

Hello all,

Is there a maximum length of time an Ovirt Node 4.2 based host can be
offline in a cluster before it would have issues when powered back on?

The reason I ask is in my lab I currently have a three node cluster that
works really well, however a lot of the time I only actually need the
resources of one host, so to save power I'd like to keep the other two
offline until needed.

I can always script them to boot once a week or so if I need to.

Thanks,

Thomas
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