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On Sunday 01 July 2007 19:19, Dr. Volker Jaenisch wrote:
> Hi Rio
>
> Rio schrieb:
> > it is FAR cheaper to run a few hosts running virtuals than to run real
> > hardware. the more hardware you run the more you increase your chances of
a
> > hardware failure. although possibly measurable, we have absolutely no
> > noticable difference in efficiency of services between virtuals and real
> > hardware.
> >
> You quite missed the point. Cost-efficiency and HA never match nor be a
> difference - they are distinct :-)
>
> Joseph critiziced that virtualisation alone is not the answer to HA -
> and he is right.
>
> The combination of virtualisation _AND_ LVS may be a answer to future
> quests for HA .
>
> We and surely several others run virtualized server-clusters with many
> virtual servers embedded into one big box.
>
> As Joseph states a critical faillure of this box will costs us as much
> cutomers as we have v-servers on this box :-)
>
> _BUT_ we have a second big box which is the realtime mirror of the first
> one by the virtue of DRBD.
> So if big box one fails ...
>
> to cite Joseph:
> > If you need failover (do virtual servers fail?)
> > why not just 5 machines (enough that you'll only loose 20%
> > on failure)?
> the second box takes over by the virtue of heartbeat and reboots the
> mirrored virtual instances.
>
> [This is not truly our aproach. We use virtual realservers spread across
> some big boxes via ipvs wich share
> some cluster-filespace. This is truely HA]
>
> Imagine the future in 2-5 years. A typical server will have 8 to 16
> CPU-cores with 2 MHz.
>
> Without virtualisation you will ony enlarge the CO2 footprint of you
> datacenter but you will not be
> cost-efficient nor you will be more HA than with distinct boxes.
>
> I post this not to put oil in the fire, but to promote a fruitful
> discussion on the benefits of combining
> virtualisation with LVS.
>
Ah. yes. and that is something I am in the process of doing as we type here. I
am working on multiple hosts having mirrors of the virtuals, then once the
director box is complete allong with whatever other support software to be
run, we will be switching over to individual private ip space for
everything 'under' the director. LVS is truly a GodSend in our situation. I
am just in a steep learning curve at the moment so progress is slow as only a
week ago I had no idea what I needed, only want I wanted to do and finally
chose LVS to make it all happen.
> Best regards,
>
> Volker
>
> --
> ====================================================
> inqbus it-consulting +49 ( 341 ) 5643800
> Dr. Volker Jaenisch http://www.inqbus.de
> Herloßsohnstr. 12 0 4 1 5 5 Leipzig
> N O T - F Ä L L E +49 ( 170 ) 3113748
> ====================================================
>
>
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--
Rio
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