Is There Intelligent Life in Storage?
Storage administrators are not noted for their deep philosophical bent. Seldom are they spotted congregating around the water cooler discussing the meaning of life or the true spiritual essence of man. Yet recently, while modern thinkers ponder the existence of intelligent life elsewhere in the galaxy, storage sages are turning their thoughts in a similar direction: Is there intelligent life in storage? And, if so, where does it reside or where should it reside?
Intelligence, it seems, has displaced Information Lifecycle Management (ILM) as the buzzword of the month in storage. Most vendors take pains to stress how intelligent their gear is, as well as to emphasize how their particular intelligent architecture is best.
"For most customers, storage intelligence will reside in multiple places: the array, the host, and the network," said Rich Bourdeau, vice president of product marketing at Incipient. "Where specific storage intelligence resides depends on the function and what the user is trying to accomplish."
Take, for example, RAID data protection. This is generally thought of as a function that best belongs in the array closest to the data it is protecting. Thus, the majority of users implement RAID data protection in the storage array. However, some customers have implemented RAID-1 mirroring in the host or network virtualization device because they want the greater availability that comes with mirroring across array frames.
"While intelligence in the host and array is not going to go away any time soon, Incipient is seeing a lot of demand from enterprise customers for intelligent storage services which reside in the network independent of the storage and host," said Bourdeau. "This enables greater freedom to migrate and copy data between different classes of storage tiers and multi-vendor storage. Customers seem to want to implement data migration, copy services and simplified SAN storage provisioning, primarily in their networks."
In Bourdeau's experience, customers prefer cross-array storage services to be placed in the network on intelligent switch platforms. The reasons he gives include better performance, platform preference and investment protection. The intelligent switch, he said, has been architected to deliver storage services at very low latency. Intelligent switch platforms, therefore, have greater throughput and processing power which, according to Incipient, is yielding much better performance than appliance- or array-based solutions.
Incipient offers the Incipient Network Storage Platform (iNSP) suite of storage services software. It provides data migration, network volume management and copy services throughout a SAN environment. These services are delivered from a common platform Cisco Systems' MDS 9000 SAN switches, with the Cisco Storage Services Module (SSM) installed.
"iNSP provides greater flexibility when migrating, provisioning and copying data in a heterogeneous, multi-vendor storage environment," said Bourdeau. "For companies experiencing rapid application data growth, iNSP's data migration feature frees up space and keeps application data localized without disruption to hosts and applications. This capability avoids the need for planned downtime."
Fabric of the Universe
Brocade Communications Systems is another fan of switch-based intelligence though the company concedes that intelligence should also exist in other portions of any environment.
Intelligence in the array, for example, enables a large disk drive to be divided into smaller virtual drives or logical unit numbers (LUNs). Similarly, many LUNs are combined and presented as a single disk to improve performance by "striping" writes and concurrently reading data from the virtualized disk.
Ultimately, network-based intelligence addresses the need to treat different devices in a common manner. For example, a business may want to replicate data from a variety of storage devices to a common storage device or replicate data from one type of storage device to a different type altogether.
"In this case, the network (which is derived from switches to create the shared storage fabric) can read data or write to/from any storage device," said Max Riggsbee, CTO of Brocade software and emerging technologies. "The ubiquity of the network enables the customer to deploy a variety of assets to address cost and performance while using a common method of management."
Brocade supports LUN-based migration and other intelligent features via its FA4-18 Application Blade, which can be attached to its storage switches.
"We are seeing the tip of the iceberg with the march toward individualization of LUNs beneath virtual servers, network booting and device authorization (specific servers being permitted to boot specific applications)," said Riggsbee. "These new requirements will combine with network-based migration, replication and volume management to enable on-demand access to storage capacity, ensure non-disruptive management of storage assets and enable dynamic business continuity capabilities."
If An EMC Array Fails in the Forest...
Not surprisingly, EMC has a somewhat different take on this thorny philosophical conundrum of storage intelligence. If an EMC disk array fails in the forest or, rather, in the data center the company is standing by with a wealth of storage hardware and software tools to lessen the impact. As a result, EMC takes a more holistic approach than Brocade, Cisco or Incipient.
"There are certain functions that each component in a storage environment excels at, and we want to ideally leverage the power of each one for intelligence," said Kevin Gray, product marketing manager at EMC. "Arrays excel at highly available storage of data and cache management, whereas switches are best at handling I/O traffic."
He points out that EMC Invista centralizes control and volume management in the network, thus freeing the presentation and manipulation of data from the underlying physical hardware. This takes much of the downtime out of data movement. EMC Invista is a network-based solution that leverages storage switches. Invista presents virtual volumes to hosts that are mapped to back-end physical storage. It uses a discrete box that connects over IP to an intelligent switch.
EMC also offers root cause analysis and troubleshooting capabilities via its Smarts acquisition. EMC Smarts was originally network discovery, monitoring and analysis software. It performs root cause analysis without needing any rules because the model reflects the actual environment, so the analysis adapts to changes in the network. Continued development of the technology since its acquisition by EMC has extended this analysis capability beyond networks into storage, servers and applications.
"Smarts is going to be very useful for the more common types of problem," said Mike Karp, an analyst at Enterprise Management Associates. "But it's the once a year or rare events that it probably won't do so well."
Vendors are from Venus, Intelligence is from Mars
Although today's storage gear has some intelligence much of it via virtualization much more is in the pipeline. Encryption, for example, is currently deployed via dedicated appliances. But vendors like Decru (part of Network Appliance) are working with Brocade and other switch heavyweights to put encryption directly into the switch.
It's been said many times in the storage world that OEMs traditionally over-promise in storage and get caught up in the latest hype. The vendors, after all, are from Venus, and user requirements like intelligence are generally far away on Mars.
The good news, however, is that there is substance behind the promises. And it won't be long before users experience the benefits.
"The best of storage intelligence is yet to come," said Karp. "Real storage intelligence has only been seen in its early forms. Analytics is probably the next big area of intelligence to find out what is really going on within a SAN or NAS pool."
Article courtesy of Server Watch