Storage virtualization phone-in the key to simplifying storage management

With a new type of storage virtualization product, multi-vendor storage resource provisioning becomes easier. Storage virtualization is not a new concept, but the concept has been brought to the attention because of the recent introduction of next-generation virtualization products by top-tier storage vendors. The methods of virtualization are not the same for each vendor, some of them put virtual functions on the network, others are virtualized in the edge or array. But regardless of the number of implementations, virtualization is all about the same basic problem: simplifying storage management.

In traditional storage settings, the intelligence required to perform critical storage functions such as data replication, disk mirroring is generally placed at the host or server level. Virtualization is that the server regards all enterprise storage devices as a whole as a large storage pool. Therefore, the traditional virtualization is to add software, device drivers, etc. on each server, such virtualization is extremely difficult to manage.

During the period from 2000 to 2001, people began to try to transfer the intelligence needed for storage virtualization to network devices, and there were some specialized devices, such as the ipstor of DataCore Company's Sansymphony and Falconstor company. Users can use these dedicated devices to make all storage devices a storage pool so that each server no longer needs to add drivers or other software. But this approach has never really been popular, mainly because large, top-tier storage vendors are not involved in this trend. "We considered Falconstor Ipstor when we installed the SAN," said Bo Christiansen, an IT consultant at SDC Udvikling, a songbook finance company in Denmark. It can integrate different storage technologies under a GUI, which is what we want. But there are some problems with the way it works, and there is also a problem with vendor lock-in. ”

IBM was the first large company to fully embrace virtualization, with the introduction of San Volume Controller (SVC) in July 2003, which can be used as a dedicated network device or as a blade to Cisco's MDS-oriented SAN switches. IBM's SVC has made considerable progress since last August when it increased its management capabilities for Hitachi Data Systems, HP and EMC arrays. This March, IBM announced that its SVC customers had reached 1000.

Hitachi has launched the Tagmastore virtualization array, and Sun has launched the StorEdge 6290 Controller/array system. EMC's Invista virtualization software is available in May this year, running on the Cisco, Brocade and McDATA-oriented switches.

These are good news for users because they are trying to cope with the explosive growth of storage and to meet regulatory requirements. Al Todd, senior it vice president of the California Regional Bank Pacific Capital Bancorp, said: "The amount of storage is growing wildly, and it is estimated to grow by 25% to 30% a year." We are unable to store enough customer data. And there's also the question of how to manage the data? "

Pacific Capital has 23TB of data, scattered throughout the company, mainly stored in IBM and EMC arrays. Todd said: "In the past, we didn't know how much storage we had, we didn't know how much capacity we used, we just added disk with new data, and we didn't manage storage." "This February, the company decided to adopt Hitachi's Tagmastore Universal storage platform, a large array that can virtualize not only its internal storage systems, but also the storage systems of other vendors plugged into the backend."

With Tagmasore, Pacific Capital retains both the investment on the IBM and EMC arrays, the full knowledge of all back-end storage systems, and the ability to significantly simplify the delivery of all storage resources. Todd said: "We've connected all the core banking systems, data warehouses and online banking systems." Now we can know exactly which systems are being used and how to tier the data. ”

Unlike IBM and EMC's network-based products, Hitachi's Tagmastore is virtualized within the array and then connected to an external multi-vendor storage system using the array's own connectivity capabilities.

Hubert Yoshida, Hitachi's chief technology officer, explained: "First connect the external storage system to the port of our device, and then our (Universal Volume manager) software searches the bus to discover the logical unit number (LUN) of all systems connected to the rear of the device, and submits a super cache image to the controller super cache.

This allows us to tier the storage system so that the data can be moved seamlessly between these layers, while the device is working properly, and only by passing the super cache image. ”

Todd says the key to tiering is to ease the burden of management and resource delivery. "The vast majority of data, say 90% or more, is not a lot of opportunities to use again after the initial use." We need to be able to migrate this data to cheaper storage systems in a simple and efficient way, and tagmastore just meets our needs. And if you need greater storage capacity, it can be provided seamlessly, even without impacting the application's normal work. ”

"Virtualization simplifies their storage environment," said Eric Muniz, network operations Manager at Sonnenschein, the Chicago law firm. Sonnenschein recently installed Sun StorEdge 6920 When implementing a comprehensive data center integration project. "We need storage systems that have both virtualization and centralized management capabilities, as well as remote boot and multipath capabilities." "Sun's equipment just met their requirements," he said.

StorEdge 6920 is similar to Hitachi's Tagmastore, but is more geared towards the mid-range market. Sonnenschein currently stores 6TB of data on the device and plans to increase storage to 16TB when it finally finishes its consolidation project. The company also has some old Hp/compaq EMA12000 arrays as well as some HP MSA1000. With Sun 6920, these devices can be managed seamlessly from a central console.

Muniz says he likes to implement virtualization in the Sun Controller unit rather than on the network. "Let's say I have a switch." If I am implementing virtualization on this switch, then I need to know exactly which virtualization areas it involves and virtualize these areas again. For this switch, I may have to stop the entire SAN. And 6920 is redundant, which in itself avoids these problems. ”

While Hitachi and Sun have opted for array virtualization, users and analysts say the network is also a good place to implement virtualization, especially for large storage systems.

"IBM and EMC have a similar approach to virtualization by placing a router between the server and the storage system," said Stephanie Balaouras, senior analyst at Yankee Group. The router retains all routing information and volume images. This approach applies to larger companies that have a large number of heterogeneous storage systems and a large number of problems with storage resources. ”

"For us, the web is the right place to implement virtualization," said Karl Rautenstrauch, a storage administrator for a large health maintenance organization in Florida. "This organization is evaluating storage virtualization products for IBM, EMC, and Hitachi.

He manages 300TB of data on EMC, HP, and IBM platforms, all via Cisco's MDS 9509 san switches. "We have so much data available, but not every server has access to that data because it is provided by application," he said. Virtualization will enable us to leverage existing equipment more efficiently. ”