New Sun code transforms x86 servers into storage arrays

Computerworld - Sun Microsystems Inc. is set to unveil on Friday open-source software that can repurpose any OpenSolaris-based x86 server into a block-based storage device capable of emulating the physical characteristics of a storage array.

Sun contributed the new code, dubbed Comstar, or common multiprotocol SCSI target, to its OpenSolaris.org open-source community last month, noted Scott Tracy, director of storage platforms at Sun. He said that Comstar promises to cut enterprise storage management costs by allowing developers to quickly add new data-transport protocols that can talk to various devices in a network.

"Customers are working overtime to make sure they get the most out of their existing hardware," Tracy said.

Sun engineers began work on the Comstar project in 2007. The code can run on any server running the OpenSolaris operating system, but it is compatible only with host bus adapters from storage networking providers QLogic Corp., Emulex Corp. and LSI Corp., Tracy said.

Comstar turns OpenSolaris servers into SCSI target storage devices that can be accessed by initiator hosts over a network. Initiator hosts supported by the software include Solaris, Microsoft Windows, Linux and VMware ESX.

According to Sun, the software simplifies the process of managing a SCSI target subsystem by creating independent modules that enable storage devices such as tape and disk drives to easily connect to transport protocols like Fibre Channel, Fibre Channel over Ethernet, iSCSI, iSER and SAS.

The software also offers concurrent access to logical unit numbers (LUN) so users can create a singular storage management interface for the new storage devices. Developers can also use Comstar to simplify LUN masking and mapping functions, execute multiple parallel transfers via SCSI commands, and perform multipathing across various data-transport protocols, added Scott.