| Re: [vhffs] is Xen really necessary on a single platform? |
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Michał Żochowski a écrit :
Hi,
I am interested in the VHFFS software and I am considering to use it
for non-profit organization hosting in Poland. I would like to try it
out first and I have one server for this purpose. In the FAQ I read:
“*I have a single computer, what is the best way to get a
fully-working hosting-system ?*
The best solution consist in using Xen. You can create several
virtual-computers on your real one. So, you can create one
virtual-computer for the VHFFS-database and the panel, and another
virtual-computer for the services. ”
Is it really required to use XEN for this purpose?
Could you please briefly explain why this is required/recommended in
reference to the VHFFS architecture?
What can I do without Xen and what is not possible to achieve?
Thanks for your time!
Kind regards,
Michał Żochowski
Hi,
In hosting environement, it's not a good idea to have all services in a
single machine, for exemple :
. DNS
You should have at least 2 separate machine to host DNS service, to make
domains survive to a reboot / shutdown / upgrade
. Mail server / relay
IMOO, you should have at least 2 boxes to act as mailrelays, to make
sure mail routing from the Interet still alive (to avoid delivery
failure when you did an upgrade).
Then one mail server should be ok to store mailboxes (if you provide
some downtime for pop3 service, it's not a big issue).
. Web server
One box could be enough.
Let me take an example :
You need 3 servers :
2 with Xen to host DNS, MX and POP3 / IMAP proxies
1 with Xen to host Web, Lists, FTP, PosrgreSQL (evt. MySQL) and Mail
Xen is recommended to separate libs / requirement / environnement
between services (for example, it's not a best practice to host mail &
web on same server, could be a big security hole).
IMOO, if you want to use less boxes (3 is a minimum), use Xen to add
security, redundancy and allow you to upgrade a service without taking
down the whole system (for exemple, try to upgrade MySQL with PHP that
link to llibs .. you have to do both if they run on same server).
--Alexandre