The combination of the two technologies allows organizations with heterogeneous storage and a SAN (storage area network) to plug the Kashya appliance into a port on the Cisco switch, allowing data replication from one SAN to another without agents.
By configuring the product this way, users can protect data in their SANs with no impact to applications and with minimum configuration, said Mehran Hadipour, vice president of business development and OEM sales for San Jose, Calif.-based Kashya Inc.
By combining forces with SANTap, the KBX5000 Data Replication Appliance no longer must rely on a host splitter driver to send a copy of the data sent, or write, to the appliance for replication.
Instead, this function is now ported to the switch, obviating the need for a host driver and allowing the system to support all operating systems.
"It uses the SANTap services to receive a reliable copy of the writes send to the Kashya appliance. This is done by using the SANTap protocol to configure the LUN [logical unit number] as a replicated LUN," Hadipour explained.
Unlike most data replication applications, where agents on the servers detect and send write I/Os to the primary volume at the local data center and a copy of the write to the appliance to be replicated, this solution doesnt require agents—which are something users dont like dealing with, said Dianne McAdam, senior analyst at Data Mobility Group LLC of Nashua, N.H.
There are many appliances that support long-distance replication, McAdam said, but eliminating the need for agents removes a source of pain for many customers—especially those with many servers and agents that must be managed.
"Customers dont like to install or manage multiple agents on the servers," she said. "With this approach, the Cisco switch not only sends the write to the local volume, but sends the write to the Kashya appliance so it can be replicated to a remote site."
The alliance with Cisco "opens up a whole new approach to delivering storage functionality using the fabric," Hadipour said. "Intelligent switches can offer a much more flexible platform that allows common SLA [service-level agreement]-driven services to be deployed for all storage on the SAN, driving the cost and complexity of data replication lower … while delivering superior functionality and performance."
An appliance like Kashya is particularly well-suited to organizations where large databases span different disk controllers, McAdam noted.
"Lets say a database spans three volumes in an IBM Shark. The Shark can replicate to another Shark and then remotely replicate those volumes to another Shark. If the path to one of those volumes fails, the Shark will suspend the replication process for all three volumes so the database is at a consistent point," McAdam said.
"But the Shark cant replicate volumes that live on other controllers. For that, you need an application like Kashya," she said. "Kashya is aware if the path to one of the volumes fails and will suspend the replication for all three volumes."
The Kashya KBX5000 Data Replication Appliance for SANTap is available in limited release, with general availability scheduled for May.