File replication on linux?

I would like to have 2 identicals web servers : one master and one slave. File newly modified/create on the master should be replicated at once on the slave (in the minute).

I do not want to use rsync because it scans all the files to calculate the delta to send. I do not want to use a distributed file system like GLUSTER because I am afraid it can accept a lot of small write. Nevertheless I can accept to wait one minute to flush all the modifications to the slave.

Do you have an idea of what tool I should use ?

Solution 1:

I have not tried it, but this may do what you are asking.

http://www.drbd.org/

Solution 2:

I fail to see why you don't want to use rsync; that is, after all, exactly what it is for...

Since you say that you don't want to use a clustered filesystem, what about using the www folder on ServerA (share/export) to mount that on ServerB as the wwwRoot. Instead of replication, ServerB is using the exact same files.