Re: RAC: why odd number of voting disks?
From: Mark D Powell <Mark.Powell_at_eds.com>
Date: Mon, 4 May 2009 12:44:17 -0700 (PDT)
Message-ID: <9361e145-e363-426a-8878-4960ec8be069_at_x6g2000vbg.googlegroups.com>
On May 4, 3:41 pm, johnbhur..._at_sbcglobal.net wrote:
> On May 4, 2:41 pm, wagen..._at_yahoo.com wrote:
>
> > As per Oracle codumentation:
> > The Oracle Clusterware enables multiple voting disks but you must have
> > an odd number of voting disks, such as three, five, and so on.
>
> > Why odd number?
>
> > Thanks for any answers/pointers.
>
> You need something to break a tie.
>
> If you had any even numbers of voting disk ( say 2 ) and a 2 node
> cluster ... what happens if one voting disk has a vote for node1 and
> the other for node 2?
>
> Voting disks among other things can lead to a rac node getting evicted
> ( thrown out ) of a rac cluster.
Date: Mon, 4 May 2009 12:44:17 -0700 (PDT)
Message-ID: <9361e145-e363-426a-8878-4960ec8be069_at_x6g2000vbg.googlegroups.com>
On May 4, 3:41 pm, johnbhur..._at_sbcglobal.net wrote:
> On May 4, 2:41 pm, wagen..._at_yahoo.com wrote:
>
> > As per Oracle codumentation:
> > The Oracle Clusterware enables multiple voting disks but you must have
> > an odd number of voting disks, such as three, five, and so on.
>
> > Why odd number?
>
> > Thanks for any answers/pointers.
>
> You need something to break a tie.
>
> If you had any even numbers of voting disk ( say 2 ) and a 2 node
> cluster ... what happens if one voting disk has a vote for node1 and
> the other for node 2?
>
> Voting disks among other things can lead to a rac node getting evicted
> ( thrown out ) of a rac cluster.
Yes, a simple as John's reply. You want an odd number to prevent ties.
HTH -- Mark D Powell -- Received on Mon May 04 2009 - 14:44:17 CDT