On 09/20/2012 06:58 PM, Jorick Astrego wrote:
On 09/20/2012 04:36 PM, [email protected] wrote:
Date: Thu, 20 Sep 2012 17:13:25 +0300 From: Itamar Heim
<[email protected]> To: [email protected] Cc:
[email protected] Subject: Re: [Users] SPM not selected after host
failed Message-ID: <[email protected]> Content-Type:
text/plain; charset=ISO-8859-15; format=flowed On 09/20/2012 05:09 PM,
Patrick Hurrelmann wrote:
>On 20.09.2012 16:01, Itamar Heim wrote:
>>>Power management is configured for both nodes. But this might be
the
>>>problem: we use the integrated IPMI over LAN power management - and
>>>if I pull the plug on the machine the power management becomes un-
>>>available, too.
>>>
>>>Could this be the problem?
>>
>>yes... no auto recovery if can't verify node was fenced.
>>for your tests, maybe power off the machine for your tests as
opposed to
>>"no power"?
>
>Ugh, this is ugly. I'm evaluating oVirt currently myself and have
>already suffered from a dead PSU that took down IPMI as well. I really
>don't want to imagine what happens if the host with SPM goes down
due to
>a power failure :/ Is there really no other way? I guess multiple fence
>devices are not possible right now. E.g. first try to fence via IPMI
and
>if that fails pull the plug via APC MasterSwitch. Any thoughts?
SPM would be down until you manually confirm shutdown in this case.
SPM doesn't affect running VMs on NFS/posix/local domains, and only
thinly provisioned VMs on block storage (iscsi/FC).

question, if no power, would the APC still work?
why not just use it to fence instead of IPMI?

(and helping us close the gap on support for multiple fence devices
would be great)


------------------------------

Message: 8
Date: Thu, 20 Sep 2012 16:24:47 +0200
From: Patrick Hurrelmann<[email protected]>
To:[email protected]
Subject: Re: [Users] SPM not selected after host failed
Message-ID:<[email protected]>
Content-Type: text/plain; charset=ISO-8859-15

On 20.09.2012 16:13, Itamar Heim wrote:
>On 09/20/2012 05:09 PM, Patrick Hurrelmann wrote:
>>On 20.09.2012 16:01, Itamar Heim wrote:
>>>>Power management is configured for both nodes. But this might
be the
>>>>problem: we use the integrated IPMI over LAN power management
- and
>>>>if I pull the plug on the machine the power management becomes
un-
>>>>available, too.
>>>>
>>>>Could this be the problem?
>>>
>>>yes... no auto recovery if can't verify node was fenced.
>>>for your tests, maybe power off the machine for your tests as
opposed to
>>>"no power"?
>>
>>Ugh, this is ugly. I'm evaluating oVirt currently myself and have
>>already suffered from a dead PSU that took down IPMI as well. I
really
>>don't want to imagine what happens if the host with SPM goes down
due to
>>a power failure :/ Is there really no other way? I guess multiple
fence
>>devices are not possible right now. E.g. first try to fence via
IPMI and
>>if that fails pull the plug via APC MasterSwitch. Any thoughts?
>
>SPM would be down until you manually confirm shutdown in this case.
>SPM doesn't affect running VMs on NFS/posix/local domains, and only
>thinly provisioned VMs on block storage (iscsi/FC).
>
>question, if no power, would the APC still work?
>why not just use it to fence instead of IPMI?
>
>(and helping us close the gap on support for multiple fence devices
>would be great)
>
Ok, maybe I wasn't precise enough. With power failure I actually meant a
broken PSU on the server and I won't be running any local/NFS storage
but only iSCSI.
But you're right with your point that in such situation fencing via APC
would be sufficient. I was mixing my different environments. My lab only
has IPMI right now, while the live environment most likely will have APC
as well.

Regards
Patrick
We don't have an APC, but we have dual psu's on two independent power
feeds with independent backup power. Would we be sufficiently protected?


it is a matter of risk management - if both will fail, you will need to manually fence the host to free resources on it (VMs or SPM role). if both power supplies go down, you usually notice and have bigger problems than this.

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