On Sat, 27 Dec 2003 03:30 am, samy lancher wrote: > Hello all, > I have a 4.5 FreeBSD server. It is our Email, web and database server. I > would like to setup a backup server so that when the main server goes down > the backup server takes over its job. Could some one please tell me the > best way to setup a backup server and also suggest some good documentation. > > Thanks in advance, > Naveen. > > > --------------------------------- > Do you Yahoo!? > Protect your identity with Yahoo! Mail AddressGuard > _______________________________________________ > [EMAIL PROTECTED] mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to > "[EMAIL PROTECTED]"
I have had a bit of a look into this myself and this is my take on it. I would like to hear of other people experiences too. There are a number of things that you have to decide on first before you go any further. These are: budget how critical the system is to downtime how much data you are willing to lose how long are you willing to wait for the second system to kick in. These will determine how you are going to build your system. You will have to keep the answers in mind when you are looking at any solution. What you seem to be looking for is a failover system. There is a fair bit written about failover systems. Googling will find you lots. Make sure that you look up linux high availability and failover as well to get a broader view. I have added some links below. There is really 2 things that you are trying to do here. Provide redundancy for the services and redundancy for the data. The services are a bit easier and cheaper than the data. The big problem is the data, especially databases. Due to their nature they cant easily be copied while live. A solution to this is a SAN. With lots of money it is easier as you can buy yourself a SAN and hook the two machines to it and host the data on the SAN. With some clever scripts from those HA sites when one machine goes down the other can take over and use the same data. There are other solutions using a fancy Y shaped SCSI cable to a external drive array. Others my be able to help here as I dont know about them. The other alternative is 2 identical machines. When you have 2 machines with the master storing data on its local drives it gets tricker. This is where you have to decide on how much data you are willing to lose. As an example we have a bsd box that rsyncs our windows fileserver ever hour. Should windas go down we run a script on the workstations remapping our drives to the bsd box. In this case we are prepared to lose up to an hours work. We are also prepared to lose say 15-30 minutes of time mucking around. In your situation perhaps what you could do is upgrade to 5.1 and rsync snapshots of your data to the secondary machine. You could use the failover setup as described on HA sites to fire up the services on the secondary machine and take over. This should work as snapshots are supposed to capture an instant in time but I couldnt guarantee it until I tested it. You would still be losing data as you could only snapshot data and transfer it in discrete intervals. A handy thing that linux has that I dont think that freebsd has is drbd. This is a block device that can mirror data across a network. If freebsd had this it would be easy to make the second machine a true mirror of the first. I wonder if they are looking at a thing similar to this in the future. Look here for some intersting reading http://linux-ha.org/ http://www.drbd.org/ http://sporner.dnsalias.org/ http://failover.othello.ch/getting_started.html _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"