[ovirt-users] oVirt - High Availability

[Eli Mesika]

----- Original Message -----
> From: "Indunil Jayasooriya" <indunil75 at gmail.com>
> To: "Eli Mesika" <emesika at redhat.com>
> Cc: users at ovirt.org
> Sent: Tuesday, October 13, 2015 6:25:59 PM
> Subject: Re: [ovirt-users] oVirt - High Availability
> 
> Hi,
> 
> Thank you very much for your reply.
> 
> I would like to know in which cases HA will happen?
> 
> 1. network failure? ( i.e , if we accidentally remove the network cable or
> if network card stopped working due to some reasons. )
> 
> 2. Server is suddenly shut-down due to power failure (i.e - NOT a proper
> shut-down ) or due to server  Hardware failure such as motherboard or
> processor.
> 
> 3. accidental reboot ?

Basically yes for all 3 
in case of 1)
There is a grace period that depends on the host load we give the host to get UP again and if that grace period passes then host is rebooted and HA VMs are atetmpted  to run on a different host 

> 
> 
> WILL HA will happen when above mentioned things happen?
> 
> 
> YES or NO?
> 
> Hope to hear from you?
> 
> 
> On Tue, Oct 13, 2015 at 7:33 PM, Eli Mesika <emesika at redhat.com> wrote:
> 
> >
> >
> > ----- Original Message -----
> > > From: "Indunil Jayasooriya" <indunil75 at gmail.com>
> > > To: users at ovirt.org
> > > Sent: Tuesday, October 13, 2015 6:13:22 AM
> > > Subject: [ovirt-users] oVirt - High Availability
> > >
> > > Hi users,
> > >
> > >
> > > I have setup OVIRT 3.5 with 2 REDHAT 7.1 hosts. Everything is ok other
> > than
> > > HA ( High Availability). To test HA, Documentation says, Power
> > Management is
> > > needed.
> > >
> > > Could you pls let me know if this Power Management is a separate Device
> > or
> > > does it come with a BRANDED Server such as HP, IBM or Dell?
> >
> > PM can be implemented by a separate card or come as part of a  BRANDED
> > Server such as HP, IBM or Dell.
> >
> > >
> > > I have seen a ILO port in HP servers. Can I use it for HA ( High
> > > Availability) in ovirt?
> >
> > Yes you can, ILO is one of the PM devices supported by oVirt
> >
> > >
> > > If power management is present in Branded Servers , Could you pls let me
> > know
> > > some Branded RHEL 7.1/CentOS 7.1 supported servers?
> > >
> > > Then, I can use it for Production use.
> > >
> > >
> > > This is an YOU TUBE video for HA.
> > >
> > > https://www.youtube.com/watch?v=uHCnXGUMaS0
> > >
> > > Is this a correct video for HA?
> >
> > Please see also https://www.youtube.com/watch?v=IuRPGU7nF1E
> >
> > >
> > >
> > > I did some research.
> > >
> > > a few URLs.
> > >
> > >
> > > http://lists.ovirt.org/pipermail/users/2013-January/011519.html
> > >
> > > http://www.ovirt.org/OVirt_Administration_Guide#Host_Resilience
> > >
> > >
> > https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Virtualization/3.5/html/Administration_Guide/sect-Improving_Uptime_with_Virtual_Machine_High_Availability.html
> > >
> > >
> > > what is Soft-Fencing Hosts ? ovirt doc gives below . (
> > > http://www.ovirt.org/OVirt_Administration_Guide#Host_Resilience )
> > >
> > > Soft-Fencing Hosts
> > >
> > >
> > > Sometimes a host becomes non-responsive due to an unexpected problem, and
> > > though VDSM is unable to respond to requests, the virtual machines that
> > > depend upon VDSM remain alive and accessible. In these situations,
> > > restarting VDSM returns VDSM to a responsive state and resolves this
> > issue.
> > >
> > > oVirt 3.3 introduces "soft-fencing over SSH". Prior to oVirt 3.3,
> > > non-responsive hosts were fenced only by external fencing devices. In
> > oVirt
> > > 3.3, the fencing process has been expanded to include "SSH Soft
> > Fencing", a
> > > process whereby oVirt attempts to restart VDSM via SSH on non-responsive
> > > hosts. If oVirt fails to restart VDSM via SSH, the responsibility for
> > > fencing falls to the external fencing agent if an external fencing agent
> > has
> > > been configured.
> > >
> > >
> > > BUT, It does NOT say how to set it up?
> > >
> > >
> > > is there any step by step doc for it?
> >
> > There is no need to set it up, soft-fencing is simply VDSM service restart
> > on the server side and is done always whether you configured PM on the host
> > or not as a first step when you host is not-responding
> >
> >
> > >
> > >
> > >
> > >
> > >
> > > HOPE TO hear from you?
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > --
> > > cat /etc/motd
> > >
> > > Thank you
> > > Indunil Jayasooriya
> > > http://www.theravadanet.net/
> > > http://www.siyabas.lk/sinhala_how_to_install.html - Download Sinhala
> > Fonts
> > >
> > >
> > > _______________________________________________
> > > Users mailing list
> > > Users at ovirt.org
> > > http://lists.ovirt.org/mailman/listinfo/users
> > >
> >
> 
> 
> 
> --
> cat /etc/motd
> 
> Thank you
> Indunil Jayasooriya
> http://www.theravadanet.net/
> http://www.siyabas.lk/sinhala_how_to_install.html   -  Download Sinhala
> Fonts
>