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Building internal storage clouds
"DIY is a big thing with internal clouds," consultant Schindler said. Do it yourself is popular because, as Illuminata's Webster noted, it simply isn't that difficult to assemble a private storage cloud (see "Essential internal storage cloud components," see below).
|Essential internal storage cloud components|
Here's a do-it-yourself parts list for building an internal storage cloud.
Source: Greg Schulz, StorageIO Group
There are many ways to design and build a private storage cloud. The simplest may be to "start with a NAS cluster, preferably with a global file system, and put on a cloud [Web] front end," i365's Allen said.
The actual storage behind the internal private cloud varies. You probably won't have a storage array as part of the private cloud. "Most will use commodity servers and fill the disk slots with low-cost drives," Nirvanix's Foskett said.
A variation: "Use racks or blade cabinets filled with Linux server blades and disk," SentryBlue's Satkunam said, adding that "the ability to use locally attached disk makes it much less expensive than SAN storage."
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," CommVault's Prahlad said. 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," Ocarina Networks' George explained. For simplicity, limit your file management options to create, read, update, delete and move/copy.
The internal storage cloud doesn't replace an organization's tier 1 storage. Production data continues to run on the high-performance FC SAN or primary iSCSI SAN where it's backed up and protected. Instead, the internal 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%," reported 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.
BIO: Alan Radding is a frequent contributor to Storage magazine.
This was first published in October 2009