[Dovecot] Hardware infrastructure for email system

[Ed W]

On 23/06/2012 13:20, Wojciech Puchar wrote:
>>>
>>> it is already enormous overshoot in hardware specs. And i do not 
>>> really catch why you have "4 in parallel" servers.
>>> And finally i cannot understand this dividing of servers just to 
>>> merging it back using VMWare.
>>
>> because it is a big difference if you have anything in a single
>> machine or splittet in virtual machines - you can move them at
>> runtime to different hosts and if you run out of ressources
>
> ok - for me it is just likes. You have higher change to have the need 
> to move at the first place doing this :)

Actually, I'm a huge buyer of "virtualisation".  There is *no other* way 
that people should be running their servers right now... (hand waving 
sweeping generalisation - obviously add context, etc, before taking 
literally).

There are various types of virtualisation solution and they have pros 
and cons, but I think there is close to zero reason not to use some kind 
of virtualisation option for all new deployments.  Probably he is using 
something clever like vmware esx - I like the theory there where you can 
literally fail over a running machine to new hardware, without even 
stopping it running, very neat.  I personally use linux-vservers which 
are almost identical to running on bare metal server (it's kind of a 
fancy form of chroot), this means I don't have commercial grade 
failover, but it only takes 5-15 seconds to "reboot" each container, so 
that's an acceptable downtime for my requirements.


Good luck!

Ed W