I am in need of a real time, two way synchronization software for Centos 5.5 / 64Bit.

Here's little explanation:

It needs to be able to perform:

1. Two way synchronization.

2. It must be realtime. By realtime means it can be almost realtime, i.e. a delay of 1 second for example is fine.

3. And the folders are on the same server.

I am currently using GlusterFS across two webservers. However, it has extremely poor small file read performance and it's slowing down my website. There's nothing more that can be done to improve this, I have already tested many configurations. As a solution, I was going to mount a RAM drive (tmpfs) that mirrors the GlusterFS web files but get the webserver to use the RAM drive.

The issue is that I need two way realtime mirroring or replication between glusterfs and the RAM drive. I need this is as Apache writes files as wells.

As I said, realtime two way synchronization across two folders. Which are in fact 2 different mounts points. The RAM (tmpfs) mount poing and the GlusterFS mount point.

I already know about:

• Rsync - Which is one way
• Unison - Which is not realtime

Please suggest me any solution free or paid.

Thanks in advance