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.
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