As systems and storage administrators wrestle with ever-growing data volumes and varying requirements for retaining data, one solution that many are considering is storage virtualization.
Virtualization is the process of taking many different physical storage networks and devices and making them appear as one 'virtual' item for purposes of management and administration. The theory is that storage virtualization offers organizations the opportunity to extend, centralize, and simplify most storage services. In other words, virtualization can provide a very efficient method for centrally managing storage that is spread across a wide variety of platforms.
The Aberdeen Group, a Boston, MA based research group, defines virtualization as a technology that enables the separation of representation of storage to the server operating system from actual physical storage. Virtualization fulfills a role for storage similar to that which an operating system does for a computer system - namely making programming and operation easier by automating resource management housekeeping. With that said, the major question on a lot of people's minds is 'can virtualization improve an organization's ROI?
According to Gartner Research, without storage virtualization one person is able to manage up to 300GB of data. With virtualization, the amount of data one person can manage jumps to 2TB. Therefore, without virtualization, the long-term cost of managing and maintaining traditional data storage infrastructure can radically outweigh the cost of acquiring and installing storage.
According to Wayne Lam, vice president of FalconStor, even in today's tighter economic environment, analysts calculate that the available pool of qualified personnel is insufficient to address the anticipated massive surge in storage demand. "The sheer volume of storage managed per person will continue to grow at a rate that many organizations have difficulty keeping up with -- storage virtualization helps alleviate these imbalances by simplifying storage management, which translates directly into lower staffing requirements," he says.
According IDC, organizations can achieve many of the benefits of uniform centralized storage through a virtual approach, which masks the complexity of the actual storage by making it appear to be a single accessible pool of information. This permits organizations to leverage existing storage and network infrastructure to gain maximum return on investment (ROI).
It seems that storage virtualization has the potential to address needs that are fundamental to all medium and large IT operations, so why then are storage virtualization firms not achieving much success in the marketplace? Lam says that storage virtualization now has a negative perception in the industry. "What doesn't help is the fact that it also has a different definition depending on the vendor," says Lam. "The reality is that virtualization is a great concept given perplexity by overly enthusiastic, though not overly accurate, vendor claims that lead to end-user confusion and an often-premature rejection of a key storage idea," continued Lam.
Another cause of user reluctance is the proprietary nature of nearly all virtualization solutions. "Once data is put into a virtual storage environment, it cannot easily be removed without undergoing a lengthy data migration process," says Lam. And, he continued, end users are always concerned about putting all their eggs in one basket, even more so when it's a virtual basket.
IDC expects virtual storage to become the standard for enterprise computing even though it alone doesn't relieve all of the issues. In addition, many organizations may opt for virtual access, either by itself or in conjunction with virtual storage. Virtualization is a means to an end, not the end in itself, says Lam. "That said, services are what virtualization was always about, and a key reason why a network-based virtualization model, with its greater flexibility, offers the most value," he continued. Lam says that the key services that enterprises are looking for include:
- Data mirroring: Provided in both synchronous and semi-synchronous modes, data mirroring creates duplicate copies of data across different storage devices. A proper solution should offer mirroring both within and across storage arrays, with no dependence on vendor or operating systems.
- Data replication: Long-distance data movement over IP, normally asynchronous, is a critical disaster recovery tool for enterprises of all sizes. Good solutions should not require special network infrastructures, nor should they be host-based in order to cut down on administrative overhead.
- Tape backup enhancements: There have been very few new developments in tape backup for the past several years. However, a network-based storage services platform can bridge the gap between disks and tape, allowing highspeed, minimal impact backups to take place.
- Point-in-time copies: Enterprises always need copies of data, whether for testing, development, reporting, or a dozen other reasons.
- Point-in-time data recovery: Restoring from tape is a major undertaking, and often does not succeed. A key new direction for storage management involves moving near term data recovery (data up to several weeks old) to disk resources, rather than tape. Disk-based restores are lightning fast (files can be recovered in 60 seconds or less) and far more reliable than tape-based recovery. Entire volumes can be restored as well.
- Application integration: Another new direction for storage services is bringing them closer to the applications they serve. No IT manager provides storage for its own sake: it is provided to service applications, such as databases, messaging systems, etc. By integrating storage services with the behavior of key enterprise applications, far greater value can be derived, as well as significantly reduced operational headaches.
So, it seems that storage virtualization is a key technology for enhancing storage availability without increasing administrative burden. But, exactly what benefits does storage virtualization encompass in regards to a comprehensive storage network solution that enables business to meet the ever-growing demand for reliable, scalable data storage?
Lam says that since virtual volumes can span across multiple physical device boundaries, a virtualized storage environment maximizes storage utilization, helping to avoid idle or unused storage space. Administrators can allocate more storage where it's being used or is almost used up, and less storage where it's not needed. This prevents the common practice of over-allocating storage in an attempt to prevent running out of space, or the equally common under-allocation-and its associated panicked race to buy and install more storage.
"Virtualization enables administrators to respond immediately, rationally, to changing storage needs. In advanced solutions, the response can even be instant-the system can be configured to monitor itself and add storage capacity automatically when pre-defined thresholds are reached," Lam says. "All of this opens the way for future storage purchases to be chosen from a plethora of available solutions, resulting in better price and capabilities," he continued. "A practical virtualization solution likewise ensures that all existing and future storage capacities can be fully integrated, realized, and presented in a simple manner and managed with ease as a single virtual volume," he concluded.