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Hi, Im very new to clustering. I have perhaps a very simple question:
I have to provide a email service, but with low spec computers which
we have in abndance. The service is Qmail, which we currently have
running on three boxes, each with different IP address and each have a
seperate MX record.
Now, I assume that the email service running behind a LVS will use a
single MX IP address x.x.x.x.
However, I have not got a clue how to go about this. Should I aim to
have two single computers linked via a serial interface (for heart
beat), or should I do something more adventurous such as link them via a
network interface.
We have 4,000 domains to look after, currently we just do forwarding,
which is not at all intensive. Once the spam and virus scanning kicks in
its a huge latency on the mail, scanning takes about 1.3 seconds per
mail, with the current load of four domains (which catch all). I hate to
think what this will be like with the other domains also.
My main objective with this is to allow myself to add computers on the
fly to the LVS pool so that I do not run the risk of bringing down the
network of email boxes when something needs an upgrade. Since we have
many domains I think that switching the lot over to a spam/virus
filtered service is not going to be smooth due to cpu/resource loads.
Here is the current network architecture in brief:
|
|
+---+---+
| cisco | 212.22.96.0/24
+---+---+
|
|
+--------+ +--ms---+ +-----+
| switch +--------+ proxy +----+ hub | 10.10.0.0/16
+---+----+ +-------+ +-----+
|
212.22.96.0/24
|
What I was thinking |
was +------+
|
+---------+--------+
| virtual server |
| 212.22.96.10 |
+---------+--------+
|
+-Mail 1-------+ |
| 212.22.96.11 +---------+
+--------------+ |
|
+-Mail 2-------+ |
| 212.22.96.12 +---------+
+--------------+ |
|
+-Mail 3-------+ |
| 212.22.96.13 +---------+
+--------------+ |
|
+-Mail 4-------+ |
| 212.22.96.14 +---------+
+--------------+
This is probably a question that has been asked many times. Currently
I spend many hours researching this question, however fruitless.
With the virtual server, which of the following must the admin create:
a)
+------------------+
| virtual server |
| 212.22.96.10 |
+--------+---------+
|
+--------+---------+
| switch/hub |
+--------+---------+
|
|
+-------------+--------+-----+
| | |
+---+----+ +---+----+ +----+---+
| server | | server | | server |
+--------+ +--------+ +--------+
b)
+--------+---------+
| switch/hub |
+--------+---------+
|
+-------------+-------++-----+
| | | |
+---+----+ +---+----+ | +----+---+
| server | | server | | | server |
+--------+ +--------+ | +--------+
|
+-------+----------+
| virtual server |
| 212.22.96.10 |
+------------------+
(I appologise for bad ascii).
Ed
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