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Lawrence D'Oliveiro 09-22-2009 12:44 AM

Anti-Virtualization
 
With sufficiently good performance per watt, could you simply abandon the
virtualization trend and pack lots of cheap, cool-running physical CPUs
into the box?

<http://arstechnica.com/business/news/2009/09/arm-attacks-atom-with-2ghz-a9-can-servers-be-far-behind.ars>

thingy 09-22-2009 01:18 AM

Re: Anti-Virtualization
 
On Sep 22, 12:44*pm, Lawrence D'Oliveiro <l...@geek-
central.gen.new_zealand> wrote:
> With sufficiently good performance per watt, could you simply abandon the
> virtualization trend and pack lots of cheap, cool-running physical CPUs
> into the box?
>
> <http://arstechnica.com/business/news/2009/09/arm-attacks-atom-with-2g...>


No....again you have a tendency to only look at the micro
level...there is more to a server in terms of heat output than just
the CPU. Then there are other aspects like high availability that
virtualisation can offer, hardware independence.....easy migration,
standard "hardware" platforms for the guests....snap shots....adequate
peak load safety margins....

Early blades were really meant to be what is discussed here, small,
low wattage boxes in quantity, Virtualisation achieves the same thing
only cheaper still....As an example we deploy a virtual guest for
about $1500~$2000, and deploy 40~50 of these in a 2 x 3U form factor
(3u for the server and 3u for its disk array...ie 1 tray of EMC SAN
disk. So about $90k for 50 guests....or about 30watts per guest
total...




Lawrence D'Oliveiro 09-22-2009 04:58 AM

Re: Anti-Virtualization
 
In message <0c54938a-
ab5a-4435-96a3-71f36deaad27@d9g2000prh.googlegroups.com>, thingy wrote:

> Then there are other aspects like high availability that
> virtualisation can offer ...


Virtualization does not offer high availability. If the hardware goes down,
ALL the virtual machines running on that hardware go down.

> Early blades were really meant to be what is discussed here, small,
> low wattage boxes in quantity, Virtualisation achieves the same thing
> only cheaper still....


Maybe not. That was one of the points in the article, in case you didn't
notice.

> ....or about 30watts per guest total...


ARM CPUs use a fraction of that. Which is the point.

Simon 09-22-2009 08:01 AM

Re: Anti-Virtualization
 
On Sep 22, 4:58*pm, Lawrence D'Oliveiro <l...@geek-
central.gen.new_zealand> wrote:
> In message <0c54938a-
>
> ab5a-4435-96a3-71f36deaa...@d9g2000prh.googlegroups.com>, thingy wrote:
> > Then there are other aspects like high availability that
> > virtualisation can offer ...

> Virtualization does not offer high availability. If the hardware goes down,
> ALL the virtual machines running on that hardware go down.


In a high availability configuration we run, it can. We have multiple
servers deployed in a HA cluster. Normally, the virtual machines run
distributed across the servers, however should one server physically
fail, then the VM's become operational on one of the remaining
operational servers.


Enkidu 09-22-2009 08:07 AM

Re: Anti-Virtualization
 
Lawrence D'Oliveiro wrote:
> In message <0c54938a-
> ab5a-4435-96a3-71f36deaad27@d9g2000prh.googlegroups.com>, thingy
> wrote:
>
>> Then there are other aspects like high availability that
>> virtualisation can offer ...

>
> Virtualization does not offer high availability. If the hardware goes
> down, ALL the virtual machines running on that hardware go down.
>

....and can be brought up seconds later on another host server.

Cheers,

Cliff

--

The Internet is interesting in that although the nicknames may change,
the same old personalities show through.

Lawrence D'Oliveiro 09-22-2009 08:19 AM

Re: Anti-Virtualization
 
In message <d0e2cdc3-0478-4a0b-99ec-4bdfc72286da@r24g2000prf.googlegroups.com>, Simon wrote:

> On Sep 22, 4:58 pm, Lawrence D'Oliveiro <l...@geek-central.gen.new_zealand> wrote:
>> In message <0c54938a-
>>
>> ab5a-4435-96a3-71f36deaa...@d9g2000prh.googlegroups.com>, thingy wrote:
>>
>>> Then there are other aspects like high availability that
>>> virtualisation can offer ...

>>
>> Virtualization does not offer high availability. If the hardware goes
>> down, ALL the virtual machines running on that hardware go down.

>
> In a high availability configuration we run, it can. We have multiple
> servers deployed in a HA cluster. Normally, the virtual machines run
> distributed across the servers, however should one server physically
> fail, then the VM's become operational on one of the remaining
> operational servers.


But there is still a few seconds' downtime, is there not, for ALL of the VMs
affected by the outage? As opposed to only a single physical machine being
affected.

The fact remains, virtualization is inherently in conflict with high
availability.

Simon 09-23-2009 07:22 PM

Re: Anti-Virtualization
 
On Sep 22, 8:19*pm, Lawrence D'Oliveiro <l...@geek-
central.gen.new_zealand> wrote:

> But there is still a few seconds' downtime, is there not, for ALL of the VMs
> affected by the outage? As opposed to only a single physical machine being
> affected.


Again, that depends upon the exact configuration. Our business has
mandated three nine's (99.9%) of reliability, so we actually have
around 10 minutes per week of allowable downtime. Should a failure
occur, this is more than sufficient for the fail-over to occur and the
inactive VM's to initialise. There are also a number of alternative
configurations that would allow near instantaneous initialisation, and
we are currently investigating these.

> The fact remains, virtualization is inherently in conflict with high
> availability.


No, not at all.


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