Tim Hildred:
If one host is down because of network interrupt or power
failure, the engine should know how many HA VMs are down and find
out the VM images on the storage domain to start the VM instances on
another host in the cluster. Why do we need power manager to be
configured?
Power management allows the Manager to start highly available virtual machines
on new hosts without worrying that virtual machine hard disk images will be
corrupted.
Imagine a situation in which the Manager cannot communicate with the host a
highly available virtual machine is running on. If the host is still running as
expected, and the virtual machine is also still running, the virtual machine is
writing to its hard disk image.
Tim,
Thanks for clarification. That is what I expected.
If the Manager starts that virtual machine on another host in the cluster, then
both virtual machine instances will try and write to the disk image, and cause
hard disk corruption.
Power management lets the Manager be sure that only one instance of the highly
available virtual machine is running, because the instance on the host the
Manager couldn't communicate cannot survive a host reboot.
Tim Hildred, RHCE
Content Author II - Engineering Content Services, Red Hat, Inc.
Brisbane, Australia
Email: [email protected]
Internal: 8588287
Mobile: +61 4 666 25242
IRC: thildred
----- Original Message -----
From: "Shu Ming" <[email protected]>
To: "Tim Hildred" <[email protected]>
Cc: [email protected], [email protected]
Sent: Monday, March 18, 2013 1:31:12 PM
Subject: Re: [Users] High Availability
Tim,
Thanks for your information. I am not sure why we need power
management to be configured for the hosts running HA virtual
machines. We only need a method to check the VM or host status and
a method to restart the VM instances with existing VM images on
another host. Is it required to force powering down the failing host
forever to make sure the failing host will not come back to live
again?
*
Power management must be configured for the hosts running the highly
available virtual machines.
*
The host running the highly available virtual machine must be part of
a cluster which has other available hosts.
*
The destination host must be running.
*
The source and destination host must have access to the data domain
on which the virtual machine resides.
*
The source and destination host must have access to the same virtual
networks and VLANs.
*
There must be enough CPUs on the destination host that are not in use
to support the virtual machine's requirements.
*
There must be enough RAM on the destination host that is not in use
to support the virtual machine's requirements.
Tim Hildred:
You might also find this helpful:
https://access.redhat.com/knowledge/docs/en-US/Red_Hat_Enterprise_Virtualization/3.1/html/Administration_Guide/High_availability_considerations.html
The topics before and after it explain a bit more about high
availability.
Tim Hildred, RHCE
Content Author II - Engineering Content Services, Red Hat, Inc.
Brisbane, Australia
Email: [email protected] Internal: 8588287
Mobile: +61 4 666 25242
IRC: thildred
----- Original Message -----
From: "Dafna Ron" <[email protected]> To: [email protected] Cc:
[email protected] Sent: Monday, March 18, 2013 4:46:51 AM
Subject: Re: [Users] High Availability
I think that there is some confusion here so I will explain what are
the
configurations for fail-over.
power management will reboot your host if a connectivity issue is
detected so all your vm's will be killed.
resilience policy will allow you to choose vm migration policy during
a
host failure and its configured in the cluster level (clusters ->
select
cluster -> general sub tab -> edit policy)
High Availability is configured only for servers type vm's and what
it
does is re-run the vm in case the pid of the vm is killed (so most
commonly, if you have power management configured, and the host is
rebooted, the vm will start automatically on a different host).
so it really depends what you want. if you want vm migration than
look
into cluster policy, if you want a specific vm to always be up and
you
don't care about the other vm's than configure power management and a
HA
vm. it really depends on what you need.
On 03/17/2013 07:15 PM, [email protected] wrote:
Is it Mandatory to have power manamement enabled? if yes what
equipment do you recommend to use with it?
Regards
Jose
----- Mensagem original -----
De: "René Koch" <[email protected]> Para: [email protected] ,
[email protected] Enviadas: Domingo, 17 Março, 2013 16:47:41
Assunto: RE: [Users] High Availability
Hi,
You have to configure power management to make high availability
working and mark the vms high availability checkbox...
Regards,
René
-----Original message-----
From:[email protected] <[email protected]> Sent: Sunday 17th
March 2013 17:28
To: [email protected] Subject: [Users] High Availability
What should I need to configure to put HA working? I mean, when a
host broke all the VM automatically move to another host.
Do I need to have Power management enabled?
Thanks
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Dafna Ron
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--
---
舒明 Shu Ming
Open Virtualization Engineerning; CSTL, IBM Corp.
Tel: 86-10-82451626 Tieline: 9051626 E-mail: [email protected] or
[email protected] Address: 3/F Ring Building, ZhongGuanCun
Software Park, Haidian District, Beijing 100193, PRC
--
---
舒明 Shu Ming
Open Virtualization Engineerning; CSTL, IBM Corp.
Tel: 86-10-82451626 Tieline: 9051626 E-mail: [email protected] or
[email protected]
Address: 3/F Ring Building, ZhongGuanCun Software Park, Haidian District,
Beijing 100193, PRC
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