Typically, backups consist of copying data from a disk system to a magnetic tape. Tape is, unfortunately, slow to write to, lacks the capacity that modern disks have, can be difficult to manage, and is very slow to recover data from. Because the purpose of a backup, as opposed to an archive, is to produce a copy of the data that can be restored if the primary data source is lost, slow recovery is a problem.
Because of these limitations, disk-based backups are gaining in popularity. Originally positioned as a replacement to tape, this method is seen as being part of a more sophisticated backup strategy. With disk-based backups, similar software and techniques are used as with tape, except that the target is a disk system. This technique has the advantage of being very fast relative to tape, especially for recovery. The disadvantages are that disk drives generally are not removable, and the data cannot be sent off-site the way a tape can.
Networked Storage
The biggest changes in data protection come courtesy of networked storage. In the
past, storage was closely tied to individual servers. Now storage is more distributed,
with many clients or servers able to access many storage units. This has been both positive and negative for data protection. On the one hand, networked
storage makes certain techniques—such as remote copy, disk-based backup, and
distributed data stores—much easier to implement and manage. The ability to
share certain resources, such as tape libraries, allows for data protection schemes
that do not disrupt operations.
However, the networked storage environment is much more complex to manage. There tend to be many more devices and paths to the data. Because one of the key advantages of networked storage is scalability, these systems tend to grow quickly. This growth can be difficult to manage, and the sheer number of devices in the storage system can be as daunting as other types of corporate networks.
Networked storage allows for multiple paths between the server or client and the data storage devices. Multiple paths work to enhance business continuity by making link failures less of a problem. There is less chance that a broken cable will cause applications and backups to fail. Overall, networked storage is more resilient. It produces an environment in which safeguarding data and recovering from failure are performed more quickly and efficiently.
Information Lifecycle Management
The future direction of data protection is in a recent concept called Information
Lifecycle Management (ILM). ILM is less concerned about the underlying data
than about the upper-level information. Information is data with context; that
context is provided by metadata, or data about the data. ILM guides data protection
by determining what type of protection should be applied to data, based on
the value of the information it supports. It makes sense to spend a lot of money on
remote copy for very valuable information. Other information may not be worth
protecting at all. ILM helps determine which path to take in making those
decisions.
KEY POINTS
- Data protection is the safeguarding of important data from destruction, alteration, or loss. It is achieved through a combination of technology, business processes, and best practices. Core components of a data protection strategy are backup and recovery, remote data movement, storage system security, and Information Lifecycle Management.
- Business drivers influencing data-loss strategies are fear of financial loss, the need to comply with regulations, attempts to maintain high productivity, and the need to meet ever-increasing customer demands.
- Risk is potential exposure to harm. An organization can be harmed when data is unrecoverable, applications fail as a result of data loss, or the time to recover data is unacceptable. The risk to a business manifests itself in lost sales, the inability to operate properly for some time, lawsuits and fines, and the effects of theft of critical information.
- Increased connectivity creates a risk multiplier. The more resources that can be affected by an event, the greater the potential harm.
- Business continuity strategies strive to keep businesses operating in the event of disaster. Data protection is a key component of business continuity.
- Data protection is changing. New practices and technologies include diskbased backup, networked storage, ILM, and remote data movement. These practices and technologies are providing system architects more options for protecting data.