Storage Virtualization Prepared by: Dr M. Mirabi

Definition of Storage Virtualization
Definition: The application of virtualization is to storage services or devices for the purpose of aggregating, hiding complexity, or adding new capabilities to lower-level storage resources.

Definition of Storage Virtualization
Storage virtualization aggregates storage components, such as disks, controllers, and storage networks, in a coordinated way to share them more efficiently among the applications it serves.
Pooling these resources in a logical way helps remove the physical barriers that would otherwise exist and maximize the full potential of these resources.
Hiding the complexity associated with all the components required to deliver storage helps simplify the operations of managing the environment and, more importantly, provides greater flexibility to meet the needs of applications.

The Characteristics of a Storage Virtualization
Enhance the storage resources it is virtualizing through the aggregation of services to increase the return of existing assets.
Not add another level of complexity in configuration and Management
Improve performance rather than act as a bottleneck in order for it to be scalable. Scalability is the capability of a system to maintain performance linearly as new resources (typically hardware) are added
Provide secure multi-tenancy so that users and data can share virtual resources without exposure to other users’ bad behavior or mistakes.
Not be proprietary, but virtualize other vendor storage in the same way as its own storage to make the management seamless.

Benefits of Storage Virtualization • Improve Storage Utilization – The main reason this happens is applications are typically allocated more storage than they need. Application and system administrators often request as much storage as they can get, rather than what they’re likely to need, since it is a scarce resource. – Due to traditional storage provisioning methods, only 30 percent of storage capacity is used and 70 percent remains unused. – Although it hasn’t been used by the application and is free, it can’t be allocated to other applications as it is dedicated to the original server.

Benefits of Storage Virtualization • Reducing cost: –

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As organizations deploy more and more applications into their environment, with consequent growth of data (often exponentially), many find they need to buy more storage more frequently, putting a real strain on budgets. As more storage is added, without effective storage management tools and processes, more IT people are needed to keep it going, and an unending cycle perpetuates. As more allocation requests are met, more people are needed to monitor the health of the infrastructure and protect the critical information by ensuring it is replicated and can be recovered in the event of a failure, requiring more storage.

With IT budgets and headcount staying flat or in many situations actually decreasing, organizations need to find more efficient and automated ways of managing their valuable information assets in the face of static or shrinking resources.

Benefits of Storage Virtualization • Managing service levels: – IT systems have become the lifeblood of most organizations in this age. With the dependency on these applications to service day-to-day business activities, making sure they deliver consistent and reliable service is critical. – It is imperative that IT staff monitor the health of their infrastructure end to end, including storage, as the key piece to delivering dependable service levels to the business.

Benefits of Storage Virtualization • Adding agility and flexibility: – For the storage infrastructure, if the storage serving an application can’t provide adequate performance or availability, traditionally system and storage administrators would stop the application, copy all the data to another location, verify it and hope that the application comes back in good shape. – Storage virtualization technology provides the ability to move data from one pool of disks to another without any need to do a manual migration.

Benefits of Storage Virtualization • Repurposing and adding value to existing assets: – When organizations compare the cost of maintenance for their aging hardware with that of buying new hardware, they are often motivated to buy new. However, with storage virtualization solutions you can breathe new life into existing assets, rather than replacing them, and repurpose them for a job with fewer requirements, or extend functionality, such as thin provisioning or remote replication to increase their value to the business.

Benefits of Storage Virtualization • Going Green: – With data storage growing at such exponential rates, together with the inefficiency of traditional storage networking, provisioning and application consumption methods, storage virtualization can go the next step by eliminating unnecessary waste. – Consolidating storage though intelligent pooling of storage resources and use of thin provisioning can delay storage purchases, resulting in far fewer unused disks spinning and consuming power. By tiering storage resources and aligning the right storage characteristics to the value of the information, organizations can use platforms that utilize disk spin-down technologies for archive data, for example, that is infrequently accessed.

Storage Virtualization • The three basic approaches to data storage are: – Direct-Attached Storage (DAS) – Network-Attached Storage (NAS) – Storage Area Network (SAN)

• A shared storage system (SAN or NAS) is required for companies to take advantage of the advanced capabilities of server virtualization, such as migrating live virtual machines, high availability, fault tolerance, and disaster recovery.

Storage Virtualization • Direct-Attached Storage (DAS): – Direct-Attached Storage (DAS) is the traditional mode of data storage. – Hard drives attached to whatever physical server is running the application. – DAS is easy to use but can be hard to manage. Note: in DAS, the storage device resides on one computer but it can be used by another.

Storage Virtualization • Network-Attached Storage (NAS): – Network-Attached Storage (NAS) is a machine that sits on your network and offers storage to other machines. – You can find specialized hardware appliances that can be filled with many hard drives and thereby provide multiple terabytes of storage. You might think of NAS as the first step toward storage virtualization. NAS provides a single source of data, facilitating data backup. By collecting your data in one place, it also avoids the problem of multiple servers needing to access data located on another server.

Storage Virtualization • •

NAS sound like a single system attached to the network, but in fact NAS has been extended to increase scalability and reliability. You can get NAS solutions that transparently cluster several NAS systems together to avoid single point of failure issues, so that if one NAS system fails, a backup takes over the work immediately.

Storage Virtualization

Storage Virtualization • Network-Attached Storage (NAS): – NAS uses standard data communication protocols to send data back and forth between a server and the NAS device. – NAS uses file-based protocols such as NFS or SMB/CIFS where it is clear that the storage is remote, and computers request a file rather than a disk block. – One advantage of NAS is that it is IP based and simple to deploy and manage. – This makes things simple but puts data traffic that’s limited to the server in DAS usage onto the corporate network, which often causes a ripple effect as additional network capacity and hardware are required to support the NAS data traffic. – The network traffic caused by moving data back and forth from the NAS to individual servers can be considerable, stressing network capacity. – The traffic can also interfere with other work carried on the network.

Storage Virtualization • Storage Area Network (SAN): – What if you have rapidly growing data storage needs and also need the assurance that your data is effectively backed up and that, more important, you’re protected from data outages due to hardware failure? – In that case, a Storage Area Network (SAN) is for you.

Storage Virtualization • Storage Area Network (SAN): – SANs use highly specialized hardware and software to transform mere disk drives into a data storage solution that transfers data on its own high performance network. – SANs provide the ability to add additional storage capacity as data storage requirements grow; – SANs can be configured to use multiple, redundant pieces of storage hardware so that data is always available, even if one or more pieces of storage hardware fail. – Comparison by NAS: • Unlike NAS, which uses standard data protocols over the corporate network, SANs use the block data communication protocol, which uses lower-level storage mechanisms than NAS-based systems to increase performance. • SANs use specialized network protocols over dedicated networks to further improve performance.

Storage Virtualization • Storage Area Network (SAN): – Within a SAN architecture, servers don’t bother with transferring data across the standard corporate network — the standard Network Interface Card (NIC) to Ethernet cable to corporate network route. Instead, they usually use their own SAN interface device called a Host Bus Adapter (HBA) to connect to their SAN. – Most SANs use Fibre Channel connectivity, a network technology specially designed to handle storage communications, or iSCSI, which is an IP-based networking standard for linking storage devices. – SANs use a specialized network protocol — either something called Fibre Channel or the alternative choice, iSCSI — for SAN network communication. – At the other end of the SAN network is a hardware device that holds drives. – This SAN device makes it easy to shift physical data storage, increase it, back it up, and even ship copies of the data to other locations to ensure business continuity in case of a natural disaster.

Storage Virtualization