When Chris Jones, manager of IT services at Blair, Neb.-based Great Plains Communications Inc., sought to improve his disaster recovery strategy, he knew exactly what he needed: synchronous mirroring of data hosted at two locations approximately 10 miles from each other. He also knew that he wanted to keep his storage array, even if it didn't support synch mirroring.
The independent local exchange service communications company has about 50 TB of storage, nearly all of which is virtualized through 200 virtual servers and 200 virtual desktops. Jones set about investigating options for synchronous mirroring capabilities, and said he learned quickly that "only the large manufacturers had that ability."
Jones's shop was running an EqualLogic iSCSI SAN array. "It was a very nice storage box," he said. "We didn't want to pull it out of service early." With VMware ESX and vMotion running at both locations, he wanted a way to balance workloads dynamically between the two data centers without buying a new storage system.
"DataCore [Software] had this offering that you could layer on top [of our existing system]," Jones said. He purchased DataCore's SANsymphony-V storage, virtualization software billed by the vendor as having the ability to auto-tier and manage storage in enterprises using incompatible devices from multiple suppliers. SANsymphony-V's feature list includes synchronous mirroring, disk pooling, high-speed caching and RAID pooling, among others. "We saw some pretty good performance improvement through [DataCore's] caching technology," Jones said. "Our primary interest was in the mirroring."
According to Jones, "If I did have storage failure, which has occurred, everything would fail over [to the other DataCore node.] Should one of those storage systems fail, the VMs [virtual machines] immediately fail over to the remote storage system and retain their operational store. At that point, you would be looking at recovering from a snapshot or, heaven forbid, you actually go back to backup these days." That means "all our VMs reside in two storage systems at any given time," he said.
SANSymphony-V enabled Jones to "break out of a single-layer approach. We no longer have to buy big, complex systems. We can buy an x86 off the shelf and DataCore adds all the SAN technologies on top of that."
DataCore's tiering works similarly to that of Dell's Compellent Data Progression, EMC's FAST VP, Hewlett-Packard's 3PAR Adaptive Optimization, Hitachi Data Systems' Dynamic Tiering and IBM's System Storage Easy Tier. But among those vendors, only Hitachi supports arrays outside of its own. SANsymphony-V's tiering works across any storage device.
Jon Toigo, CEO and managing principal at Toigo Partners International, runs DataCore in his own environment and tells IT customers to look at DataCore to avoid "buying feature-encrusted gear that jacks up the price.
"DataCore can overlay on top of anything that connects to the server and manage it all as one pool," Toigo said. "It leverages all the load balance, receives all the writes into memory on the server and writes to non-volatile RAM. The system thinks your storage is four times faster because it's going down to RAM."
Toigo noted, however, "I don't want to overstate one thing. You don't have management of the underlying infrastructure -- you have management of the services provided by storage. Storage arrays are prone to failures much more than people realize; the interconnects, fans, power surges, all of that can fail."