[Engine-devel] [Design for 3.2 RFE] Host Power Management Multiple Agent Support
On 11/16/2012 03:06 AM, Eli Mesika wrote:
Requirements: http://wiki.ovirt.org/wiki/Features/HostPMMultipleAgents DR : http://wiki.ovirt.org/wiki/Features/Design/DetailedHostPMMultipleAgents _______________________________________________ Engine-devel mailing list Engine-devel@ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel
Lon - thoughts on this?
On 11/16/2012 11:35 AM, Itamar Heim wrote:
On 11/16/2012 03:06 AM, Eli Mesika wrote:
Requirements: http://wiki.ovirt.org/wiki/Features/HostPMMultipleAgents DR : http://wiki.ovirt.org/wiki/Features/Design/DetailedHostPMMultipleAgents _______________________________________________ Engine-devel mailing list Engine-devel@ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel
Lon - thoughts on this?
Looks the first thing that jumps out is that it looks like you can have: - do this one off action && do this one off action - do this one off action || do this one off action So, try device A, and if this fails, try device B - or, if it's really two ports on device A (but two calls), both must succeed. One thing I wonder is whether these use cases are covered. 1) With WTI units and similar, many have two independent power rails. This means that if someone trips over one of the power cables going to the power switch unit, the host will still have power. A || (B && B') ^ ^ ^ | +----+---- WTI dual-rail remote power switch | (two ports used - one on each power rail) | +--------------- iLO / IPMI / etc. 2) More common with the smaller APC units is that most have a single power supply rail. For power redundancy, it's not recommended to ever plug both power supplies in to the same single-rail APC unit. A || (B && C) ^ ^ ^ | | +---- APC device 2 port 1 | +--------- APC device 1 port 1 +--------------- iLO / IPMI / etc. E.g. try the iLO device first, but if that fails, you need to cut off both power supplies (then on). This is presumably less harsh to the machines. I also would not /necessarily/ limit things to two power supplies, but I think two power supplies is the 99% use case. I'll keep looking. -- Lon
----- Original Message -----
From: "Lon Hohberger" <lhh@redhat.com> To: "Itamar Heim" <iheim@redhat.com> Cc: "Eli Mesika" <emesika@redhat.com>, "engine-devel" <engine-devel@ovirt.org> Sent: Friday, November 16, 2012 7:42:12 PM Subject: Re: [Engine-devel] [Design for 3.2 RFE] Host Power Management Multiple Agent Support
On 11/16/2012 11:35 AM, Itamar Heim wrote:
On 11/16/2012 03:06 AM, Eli Mesika wrote:
Requirements: http://wiki.ovirt.org/wiki/Features/HostPMMultipleAgents DR : http://wiki.ovirt.org/wiki/Features/Design/DetailedHostPMMultipleAgents _______________________________________________ Engine-devel mailing list Engine-devel@ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel
Lon - thoughts on this?
Looks the first thing that jumps out is that it looks like you can have:
- do this one off action && do this one off action - do this one off action || do this one off action
So, try device A, and if this fails, try device B - or, if it's really two ports on device A (but two calls), both must succeed.
One thing I wonder is whether these use cases are covered.
1) With WTI units and similar, many have two independent power rails. This means that if someone trips over one of the power cables going to the power switch unit, the host will still have power.
A || (B && B') ^ ^ ^ | +----+---- WTI dual-rail remote power switch | (two ports used - one on each power rail) | +--------------- iLO / IPMI / etc.
2) More common with the smaller APC units is that most have a single power supply rail. For power redundancy, it's not recommended to ever plug both power supplies in to the same single-rail APC unit.
A || (B && C) ^ ^ ^ | | +---- APC device 2 port 1 | +--------- APC device 1 port 1 +--------------- iLO / IPMI / etc.
E.g. try the iLO device first, but if that fails, you need to cut off both power supplies (then on). This is presumably less harsh to the machines. I also would not /necessarily/ limit things to two power supplies, but I think two power supplies is the 99% use case.
I'll keep looking.
Thanks Lon I had added those questions in the Feature Talk page : http://wiki.ovirt.org/wiki/Talk:HostPMMultipleAgents I will discuss those cases with Simon tomorrow and try to answer those questions
-- Lon
On 11/17/2012 04:14 PM, Eli Mesika wrote:
I'll keep looking.
Thanks Lon I had added those questions in the Feature Talk page : http://wiki.ovirt.org/wiki/Talk:HostPMMultipleAgents I will discuss those cases with Simon tomorrow and try to answer those questions
Hi, Procedural question - is it preferred that I write comments here, or on the wiki page? -- Lon
On 11/19/2012 04:37 PM, Lon Hohberger wrote:
On 11/17/2012 04:14 PM, Eli Mesika wrote:
I'll keep looking.
Thanks Lon I had added those questions in the Feature Talk page : http://wiki.ovirt.org/wiki/Talk:HostPMMultipleAgents I will discuss those cases with Simon tomorrow and try to answer those questions
Hi,
Procedural question - is it preferred that I write comments here, or on the wiki page?
not sure about others, but i find it easier to track comments on email before the conclusion is updated to a wiki
----- Original Message -----
From: "Itamar Heim" <iheim@redhat.com> To: "Lon Hohberger" <lhh@redhat.com> Cc: "Eli Mesika" <emesika@redhat.com>, "engine-devel" <engine-devel@ovirt.org> Sent: Monday, November 19, 2012 5:54:07 PM Subject: Re: [Engine-devel] [Design for 3.2 RFE] Host Power Management Multiple Agent Support
On 11/19/2012 04:37 PM, Lon Hohberger wrote:
On 11/17/2012 04:14 PM, Eli Mesika wrote:
I'll keep looking.
Thanks Lon I had added those questions in the Feature Talk page : http://wiki.ovirt.org/wiki/Talk:HostPMMultipleAgents I will discuss those cases with Simon tomorrow and try to answer those questions
Hi,
Procedural question - is it preferred that I write comments here, or on the wiki page?
not sure about others, but i find it easier to track comments on email before the conclusion is updated to a wiki
Have no problem with that, lets use the email and I will put the summary on the wiki
On 11/19/2012 04:48 PM, Eli Mesika wrote:
----- Original Message -----
From: "Itamar Heim" <iheim@redhat.com> To: "Lon Hohberger" <lhh@redhat.com> Cc: "Eli Mesika" <emesika@redhat.com>, "engine-devel" <engine-devel@ovirt.org> Sent: Monday, November 19, 2012 5:54:07 PM Subject: Re: [Engine-devel] [Design for 3.2 RFE] Host Power Management Multiple Agent Support
On 11/19/2012 04:37 PM, Lon Hohberger wrote:
On 11/17/2012 04:14 PM, Eli Mesika wrote:
I'll keep looking.
Thanks Lon I had added those questions in the Feature Talk page : http://wiki.ovirt.org/wiki/Talk:HostPMMultipleAgents I will discuss those cases with Simon tomorrow and try to answer those questions
Hi,
Procedural question - is it preferred that I write comments here, or on the wiki page?
not sure about others, but i find it easier to track comments on email before the conclusion is updated to a wiki
Have no problem with that, lets use the email and I will put the summary on the wiki
Sure. I read the response on the wiki. It sounds like for now, the level of flexibility I described isn't desired. The deployments involving remote power with dual power supplies will be covered adequately by this (e.g. if you turn on 'concurrent'). The solution is simple enough. -- Lon
participants (3)
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Eli Mesika -
Itamar Heim -
Lon Hohberger