By Dave Simpson
In April, Melville, NY-based startup FalconStor will begin shipping a software suite -- dubbed IPStor -- that provides storage virtualization and aggregation, while at the same time enabling both block-level and file-level storage traffic over standard IP networks.
"IPStor comprises not only end-to-end IP-based storage networking, but also a full-blown virtualization engine," says Steve Duplessie, senior analyst at The Enterprise Storage Group consulting firm, in Milford, MA. Duplessie says that FalconStor is the only vendor offering virtualization over IP.
On the storage virtualization front, FalconStor will compete with vendors such as Compaq, DataDirect Networks, DataCore Software, IBM/Tivoli, StoreAge, StorageApps, Veritas, and Vicom. Virtualization aggregates heterogeneous physical storage devices into a logical storage "pool" to facilitate administration and management. (For more information on storage virtualization, see the Special Report in the January issue of InfoStor or click here.
However, according to company president and CEO ReiJane Huai, FalconStor hopes to differentiate itself from other storage virtualization vendors in a number of ways. For one, FalconStor's software-only approach, which is based on Linux and packet tag queuing technology, can operate at the block level -- as opposed to the LUN or file level -- and does not require LUN masking. Huai claims that this gives IPStor an edge in terms of granularity.
IPStor consists of two software stacks: one that handles block-level (e.g., storage area network) traffic, and a stack that handles file-level network-attached storage services (including the NFS and SMB/CIFS protocols). As such, the software enables end users to combine SAN and NAS functionality.
The Linux-based code runs on an Intel server, and is implemented in a symmetrical configuration (the server resides "in-band," in the data path between the application servers and the storage devices.) The software also provides active-active server failover, eliminating the single point of failure that characterizes some in-band virtualization "appliances."
In addition to aggregation and virtualization, IPStor provides services such as high availability, snapshot copies, mirroring, and "zero impact" backup and recovery.
Huai claims that IPStor works with existing protocols such as SCSI, Fibre Channel and SSA, as well as with emerging protocols such as iSCSI and InfiniBand. In the future, FalconStor will support iSCSI as well as its own proprietary implementation, which is based on the remote procedure call (RPC) external data representation (XDR) specifications.
"We have our own IP-based protocol that we built on UDP, which takes care of flow control, serialization, etc," Huai explains, "It's a lightweight version of TCP/IP."
ExtremeLabs Inc., an independent testing organization, conducted three benchmark test series comparing IPStor to server-attached disk subsystems. The three tests were based on the IOMeter, eTestingLabs WebBench and NetBench benchmark programs. ExtremeLabs discovered that the difference in performance between server I/O using a local disk subsystem and the IPStor approach ranged from a rare 0.6 percent latency to a 7.2 percent gain in performance for the IPStor approach.
ExtremeLabs concluded: "The results were chilling: IPStor SANs under test conditions outperformed local subsystems, and were rarely the source of any disk I/O latency." For complete test configurations and conclusions, visit www.extremelabs.com.