The Situation:

There was a requirement in GIS platform to reliably replicate data in NTFS folders between the GIS main server room and the disaster recovery site.

The Choice:

 GIS Infrastructure team had 2 options for data replication:

1)    SAN replication: through proprietary software the data could be asynchronously replicated disk-to-disk in the SAN unit in GIS main server and another SAN unit in disaster recovery site. This involved acquiring the licenses and support for the software, as well as additional networking equipment for fibber to TCP/IP conversion.

2)    Host based replication: through the data replication option in Microsoft DFS, data between hosts at main and disaster recovery sites could be replicated as long as there is a TCP/IP network connection between them. There is no additional cost for DFS license.

Option #2 was selected due to its simplicity and lower cost.

The Challenge:

 Data should be replicated without affecting the existing critical file permissions.

The Process:

Two test machines were prepared with Windows 2003 Server operating system and with DFS RPC patches.

The machines were connected together through a LAN switch. The network bandwidth was 10Mbps.

Data folders containing files with NTFS permissions were replicated from one to another.

The Result:

While retaining the existing structure and file permissions, an approximate data transfer rate of 250MB per minute with the network bandwidth of 10Mbps between two hosts was achieved. This is an acceptable rate for replicating the data between GIS main and disaster recovery sites.

The Impact:

By successfully completing the pilot project for data replication through Microsoft DFS, the GIS Infrastructure team positively tested a very economical and easy to administer data replication technique, which will save Dubai Municipality approximately124801$ in Implementation and 36,000$ in Operation Cost for alternative technology.