[CentOS] how do i have a clone centos server

[Mail Administrator]

Dear All,

I do have a centos 5 srver running the following. the server is a dell pc
with standard config

1 gb ram
120 gb ide hdd
3.2 ghz cpu
NIC


Mail server
Dns Server
webmail
Mailscanner

now i would like to have another server like mirroring this server ..
so incase there is any problem with this server the other server is always
online and the problem server could be fixed without our users gettin
affected

apprecite if anybody can help giving some clues or is there any software
avaliable.
also is the hardware in both servers have to be identical or it can be
different


thnks n regards


simon




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