The IT team at the fee-paying school decided it needed some form of replication for disaster recovery purposes after it implemented a second SAN two years ago.
The bulk of the data is students' work in Microsoft Word and Access plus school financial information. Simon Marriott, IT manager with Bradford Grammar School, says the institution needed reliable failover between the two SANs and quick restore times.
He says, "We implemented a two-node cluster a few years ago and decided we wanted to create real time disaster recovery with the two SANs, with real time failover. We estimated at the time it would take one month to restore files and that was unacceptable. IT is used to teach virtually every subject and students submit crucial coursework electronically, so we have to treat it as irreplaceable."
The product Marriott and his team opted for was FalconStor's IPStor Continuous Data Replication plus application-aware Snapshot Agents with the TimeMark option. CDR provides real time replication from one SAN to the other while Snapshot Agents takes copies of data stores for point-in-time recovery purposes. The TimeMark option provides the ability to instantly recover a single file or entire volume back to a known good point in time.
Project cost was £120,000 which included the two servers which run the FalconStor software. Data passes through the FalconStor-equipped devices and block level changes are recorded.
For Marriott the chief benefit is peace of mind. He says, "We now have real time replication of data and have snapshots we can roll back to of any specific point in time. If, for example, there are errors inputting financial data that become apparent later we can roll back to a previous point in time and trace what went wrong."
FalconStor won out over two other contenders – IBM hardware-based replication and software from Neverfail – on the basis of features and future flexibility, says Marriott. He says, "IBM were pushing us down the route of taking their hardware-based replication, but we didn't want to be locked in to their products. The cost of IBM was going to be similar to that of FalconStor, but for the same price we'd get a lot more."
He adds, "We felt Neverfail wouldn't perform as well as IPStor. Also IPStor's features allowed for a multitude of options in the future that the Neverfail product couldn't compete with."
The main challenges experienced by Marriott's team during implementation were getting the IBM SAN to work with FalconStor as well as some Fibre Channel cabling issues. There were problems with FalconStor recognising partitions on the IBM SAN, but they managed to work around these during implementation and eventually created new ones.
Marriott says, "We also had to create 100 pairs of Fibre Channel cable to run between the two SANs, the switches, servers and the FalconStor unit to provide complete redundancy. It was a headache that resulted form having a Fibre Channel environment. We had looked at iSCSI solutions but decided it wouldn't provide fast enough throughput for real time replication."
Continuous data replication is a fast-growing product area, according to Tony Lock, programme director with analysts Freeform Dynamics. Research by the organisation late last year found that CDR is second only to distributed data replication in terms of growth of adoption.
Lock says the key questions to ask when considering procuring continuous data replication tools are compatibility with existing systems and efficiency of recovery. He says, "The basic questions to consider with any product of this type are, will it run on the platforms I have and with the applications I need it to and will I be able to recover from it successfully? There are cases of especially databases type files that will provide inconsistent data sets or even necessitate full platform rebuilds if you try to recover from them."
He adds that it is worth determining to what extent a product really does replicate in real time as many do not provide true real time performance. "There are a wide range of definitions of 'real time' and very few are genuinely so," says Lock.