Re: [ceph-users] Ceph mon quorum

Re: [ceph-users] Ceph mon quorum

[Gregory Farnum]

On Fri, Apr 5, 2013 at 10:46 AM, Dimitri Maziuk <dmaziuk@bmrb.wisc.edu> wrote:
> On 04/05/2013 12:32 PM, Gregory Farnum wrote:
> ...
>> Or just a VM running somewhere that's got a VPN connection to your
>> room-based monitors, yes. Ceph is a strongly consistent system and
>> you're not going to get split brains, period. This is the price you
>> pay for that.
>
> Yeah, well. You are in building A talking to the servers in room A. The
> building catches fire, you run over to building B and connect to the
> servers in room B. Unfortunately your uplink was in A's basement, it is
> now powered off and flooded, and so mon.b has no connection to
> mon.in.the.cloud and your data is unreachable.
>
> Which means both building B and mon.in.the.cloud were a total waste of
> your time and money.

Obviously you would need them each to have their own independent
connection, yes. I'm sorry if this aspect of the system is problematic
for you, but it's pretty fundamental to any distributed or cloudy
system that chooses consistency over availability.
-Greg
Software Engineer #42 @ http://inktank.com | http://ceph.com

Re: [ceph-users] Ceph mon quorum

[Dimitri Maziuk]

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On 04/05/2013 12:50 PM, Gregory Farnum wrote:

... I'm sorry if this aspect of the system is problematic
> for you, but it's pretty fundamental to any distributed or cloudy
> system that chooses consistency over availability.

It isn't actually -- as long as 'chooses consistency over availability'
is printed in big bold letters on the front page of the sales brochure. ;)

-- 
Dimitri Maziuk
Programmer/sysadmin
BioMagResBank, UW-Madison -- http://www.bmrb.wisc.edu


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