Dear All, I have the following setup which is the heart of our organistion and runs the following for a long time Centos 5.0 server which is used as a Primary Mailserver running sendmail about 400 users mailScanner Primary DNS server using bind Webserver running apache squirrel mail web server i also do have a another centos secondary DNS server and same machine used as my secondary mail server with no mail users Currently i have been following a little crude way of backup i shut down the Primary machine and I use clone Gozilla to make a duplicate of the original disk and keep it standby i do it weekly basis which is really a crude way i am jus googling arround for a solution in where i could have online mirroring of another machine i could have an identical hardware machine which could be running online so if the first machine fails the second one is avaliable instantly also if i create a new user or a new mail user ther user is replicated on both machine if i upgraded or install any software on one machine it is replicated on the other automaticalu.. so we have total redundancy can it be done i was googling arround and actually found linux heartbeat but could not really get the hang of it. to my understanding heartbeat works on service which one would like to mirror but for me i would like disk mirroring on different servers any body has done the above apprecite your advice and help regards fabian -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.