There are many ways to design and build an internal, private storage cloud. The simplest may be to "start with...
a network-attached storage [NAS] cluster, preferably with a global file system, and put on a cloud [Web] front end," said David Allen, chief technology officer (CTO) at i365, a Seagate Company.
According to Anand Prahlad, CommVault's vice president of product development, the key to building a scalable internal storage cloud "is to start with a lot of little boxes and scale out by adding more boxes." You get data protection through redundancy by replicating the data among the many nodes. To get quality of service, different nodes can have different service performance attributes.
The glue that ties it all together is "a global file system presenting a single name space," Prahlad noted. This may also entail a virtualization and metadata layer.
Management of the internal storage cloud should be simple. "You have to look at websites like Amazon and Facebook for your model. You want whole file storage over HTTP," explained Carter George, vice president of products at Ocarina Networks. For simplicity, limit your file management options to create, read, update, delete and move/copy.
Greg Schulz, senior analyst and founder of Stillwater, Minn.-based StorageIO Group, offers this do-it-yourself parts list for building an internal storage cloud:
- Global or clustered file (NAS) system (includes virtualization and management capabilities)
- Commodity servers and low-cost storage (SAS direct-attached storage [DAS], JBOD, PCIe RAID)
- Cost-effective network bandwidth services
- Cloud personality interface depending on application need (NFS, SMTP/POP, HTTP, DICOM, REST, SOAP, XML)
- Object or metadata management layer, including applicable data protection and security tools
Cloud not a replacement for tier 1 data storage
The internal storage cloud doesn't replace an organization's tier 1 storage. Production data continues to run on the high-performance Fibre Channel (FC) storage-area network (SAN) or primary iSCSI SAN where it's backed up and protected. Instead, the internal storage cloud would be used for all the file-based data eating up primary disk space and complicating backup and recovery strategies, as well as for email, archival, media and compliance data. That data is still active, widely used and changed; it needs to be stored and shared but without the expense, performance and service levels associated with tier 1 production storage.
The latest Wave study (January 2009 to May 2009) from New York City-based TheInfoPro asked about interest in clouds in general. "The interest level was light, maybe 12% to 15%," said Robert Stevenson, TheInfoPro's managing director of storage research. "Most [respondents] had no plans for the cloud." Large companies apparently aren't clamoring for internal storage clouds or cloud computing at this point.
They may, however, already be mimicking internal storage clouds but not realize it as they pop virtualized servers with attached disk onto the network. It's a small step from that to an actual internal storage cloud.
Alan Radding is a frequent contributor to SearchStorage.com.
This material originally appeared in Storage magazine.