----- Original Message ----- > From: "Lon Hohberger" <l...@redhat.com> > To: "Itamar Heim" <ih...@redhat.com> > Cc: "Eli Mesika" <emes...@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 > _______________________________________________ Engine-devel mailing list Engine-devel@ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel