Am 09.02.2012 23:56, schrieb Luis Motta Campos:
> On 9 Feb 2012, at 23:03, Reindl Harald wrote:
>> which downtime?
>> replication anywhere?
>> why do you believe this?
>> this is not a technical problem
>> but where is te problem?
>> not if it is done right
> Dear Reindl,
> From your questions I can see that you are indeed doing your homework. :) I'm glad to
> learn this.
i think so :-)
> I couldn't devise a way I would feel comfortable deploying a SAN on my environments
> having to stand some write downtime - this is annoying and I would like to avoid it.
> Of course,
> YMMV, and you might be able to find a better solution.
if you get a new SAN storage however it is implemented start a replication slave
there, prepare all services to switch to this slave and so finally the downtime
is nearly at zero and can be well scheduled
there is no difference to any other storage because the storage is
transparent to the application layer
the point why i recommend virtualization (and yes i know about the overhead)
is that if you have your servers once at a shared SAN with VMware you
can in the future move you servers to new hardware without any downtime
and can implement failover on the VM level, so your mchines are moved
automatically at failures, with the right license you can even
do a storage-vmotion and move your running machines some years
later to a new SAN storage
and this benefits and the overall fewer needed hardware gives you
the option to buy REAL FAST hardware which defends the virtualization
overhead instead having much more cheaper machines without this
overhead but with degraded power at all
example -> RAM:
what is better - having two machines with 32 GB and possibly one
needs only 28 finally but the other would need 36 GB or have
one host with 64 GB where you can dynamically allocate ressources
to your guests and if you increase the memory all guests can
> Non-technical issues and how to justify costs are part of my attributions as a DBA it
> be that you're lucky enough to work for some business that stopped caring about how
> technology costs, and this makes your life much simpler and easier. :) Lucky you.
not "stopped caring about how much technology costs" but started caring
what benefits technology has and how much crappy partly solutions
in summary costs over the whole lifetime
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