DataCore Software Corp. is previewing the next major release of its SANmelody and SANsymphony storage virtualization software at VMworld Europe 2009 this week. SANmelody 3.0 and SANsymphony 7.0 will ship next month with 64-bit software architectures and new features for virtual server users.
SANsymphony virtualizes enterprise storage-area networks (SANs), while SANmelody is aimed at smaller Fibre Channel (FC) and iSCSI SANs up to 32 TB. Both provide management features such as virtual disk pooling, synchronized mirroring for high availability, load balancing and thin provisioning.
The native 64-bit controller software lets SANmelody and SANsymphony support a large cache on the physical server. Previous releases were limited to a 20 GB cache, but the new versions can theoretically support up to 1 TB.
A terabyte of cache "is at the far edge of reality for most normal sites today," said Jack Fegreus, CEO at Southborough, Mass.-based openBench Labs, a consultant and product testing firm. But a large site with big servers and a lot of virtual machines (VMs) might have 256 GB of cache. In a few years time, given Moore's Law, 1 TB of cache may well be average, Fegreus said.
Fegreus said the increased cache will allow for denser consolidation of servers into virtual machines, and could improve the performance of VM backups by minimizing I/O to disk.
Another new feature for virtual server support is the DataCore Transporter Option for SANmelody and SANsymphony, which performs conversion between physical and virtual servers. This utility allows a server to be converted from a physical Windows box to a Microsoft Corp. Hyper-V image, then to a VMware ESX image, and then back to a logical unit number (LUN) mapped to a physical server.
"Most users aren't currently running multiple virtual servers, but most people eight years ago didn't think people would be running both Linux and Windows," Fegreus said.
DataCore customer Themis Tokkaris, systems engineer at Tucson, Ariz.-based international pest control company Truly Nolen of America Inc., said he was looking for something that would convert his virtual machine images back to physical servers. "It's also an open idea," he said. "If I'm not happy with ESX in the future, I'm not stuck with it."
Organizations running VMware ESX have the option of using a new free plug-in for VMware Inc.'s Virtual Infrastructure Client, which offers "cleaner visibility and easier-to-understand mappings and paths," according to James Price, DataCore's vice president of product and channel marketing.
The DataCore upgrades also add a way to reclaim free capacity on volumes using thin provisioning.
Server and storage convergence continue
DataCore isn't the first to market with most of these features. Vendors have been adding 64-bit software support over the last year or so, and Symantec Corp., Double-Take Software Inc. and others have products that do physical to virtual conversion -- though those products are focused on the data protection space. Compellent Technologies Inc. added free space recovery for thin provisioning to its Storage Center SAN a year ago.
However, Fegreus says DataCore's combining these features into a server-centric approach looks like the wave of the future for networked storage as integration increases between SANs and servers.
"The server HBA [host bus adapter] then has to start acting like a switch port in a SAN, and classes of HBAs and servers start to complicate matters," he said. "There's going to be a lot of storage rethink going on."
Storage/server vendors such as Sun Microsystems Inc. and Hewlett-Packard (HP) Co. have taken a similar approach, especially with storage for virtual servers. Sun argues that servers and Ethernet networks are overtaking separate storage arrays and Fibre Channel fabrics. HP last year acquired LeftHand Networks Inc., which sells SANiQ software that runs on commodity HP servers. HP positions its LeftHand platform for attachment to server virtualization projects.