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What is hierarchical storage management and what are its benefits?
Hierarchical Storage Management (HSM) is a technique that uses two or more levels of data storage to reduce volatility and lower costs. Using HSM, a greater amount of data less frequently accessed is stored on slower, less expensive media (such as magnetic tape) while the more active online information resides on higher-speed, higher-cost devices (such as hard disk arrays). By utilizing these different tiers of storage, organizations can access their data simultaneously, regardless of physical location.
Reduced Costs and Increased Storage Density
HSM systems provide a low-cost way to grow data capacity. Traditional storage systems have served only one purpose: to store as much data as possible as inexpensively as possible. As a result, most IT organizations have relied on a single, linear structure of data from newest to oldest, from fastest to slowest, and from highest density to lowest density. The result is that many organizations are running out of physical space in their current storage environments.
Complexity and Expensive Operations
How does hierarchical storage management work in practice?
Data is organized into groups of files and then migrated or ‘moved’ to the appropriate store based on its access frequency. The hierarchy could consist of the following tiers: Primary Storage, Secondary Storage, Tertiary / Offline Storage. As primary data is accessed, it takes on the characteristics of secondary storage. If it is not accessed for a reasonable amount of time, the data could be ‘moved’ to tertiary storage. Data can be moved to different tiers in different circumstances. The default behavior is ‘moved’ data to the tier where it has the highest access frequency. Files that are moved from one tier to another are typically renamed, and then put back into their original tier. Files are not moved or renamed when they are accessed for the first time, unless otherwise specified by the system administrator via some form of permissions setting or by other factors such as a file system access privilege deficiency.
What solutions are available for implementing a hierarchical storage management system?
There are a number of companies that provide HSM software. A variety of HSM and tape backup products, such as the HP StorageWorks P9500 and Symantec NetBackup 6.0, allow enterprises to improve capacity utilization, increase application availability and reduce administration costs. In addition, HSM technologies can help organizations comply with regulatory requirements such as the Sarbanes-Oxley Act of 2002 (SOX), the Health Insurance Portability and Accountability Act (HIPAA), and the Payment Card Industry Data Security Standard (PCI DSS).
Hierarchical storage management (HSM) is an information technology (IT) process in which the data on a computer system’s most active, or hottest, storage tier(s) is automatically migrated in order to make more space available.
The term “non-uniform memory access” refers to systems that use hard disks with different access time as opposed to all having the same access time. A non-uniform memory access computer uses a hierarchy of storage devices (e.g., a magnetic hard disk, optical disk, and RAM), each with different access times. The fastest storage device is reserved for the system’s main memory, while other devices with greater storage capacity are used as auxiliary storage. A program running on the computer will load most of its data into cache memory in main memory, while keeping comparatively little in slower auxiliary storage.
How can you choose the right solution for your business or organization’s needs?
Try to use a solution built for a particular environment or applicaiton. Do not purchase products that don’t fit your needs. For example, do not purchase tape backup systems for which you will only back up Windows 95 files because IT administrators may not use that type of information. Also, check the vendor’s commitment to the roadmap of your solution. Does the vendor have a roadmap for improvements of your solution or new products you can buy in 2-5 years from now?
There are many products available. Each company has its own flavor of the solution they feel is best for their users. Make your decision based on the features that can be used in your environment and what you will use the product for most.
The solution must support your specific needs. For example, you may need to rely on a disaster recovery (DR) solution that uses tape backup solutions because it supports:
Tape-based backups to minimize data loss due to failures of magnetic storage media like hard drives.
Nothing on a hard drive can go bad if there is no hard drive. Most tape systems don’t have fans or moving parts to fail so they are more reliable and less expensive to maintain than the typical solution based on magnetic media.
What are the potential challenges of implementing a hierarchical storage management system?”
If you are using a new HSM product, be ready for migration headaches. Migration tasks can be difficult and time-consuming as applications and data need to be checked to ensure data integrity. Also, check products’ interoperability in your environment. Make sure that the technical architecture of your selected product is compatible with components already in use within your organization or in other environments. Finally, once you have purchased the HSM system and software, be prepared to continue to work with the vendor on upgrading the system. HSM vendors are constantly making enhancements, and you will need to work with them to support those enhancements in your environment.
What are the potential challenges of implementing a hierarchical storage management system?
Background: “…hierarchical storage management solutions” – To use the phrase “hierarchical storage management solutions” is to be vague on purpose. In other words, they do not reveal any information at all. What this sentence means is that you are not sure what is included in a hierarchical storage management system, but then it says that you should use one anyway. It appears that the High-Performance Computing Center at UC Berkeley was not totally categorical in their statement, as they continue: “These solutions are commonly referred to as “hierarchical storage management systems” (HSMS). Hierarchical storage management provides a unified view of all data and enables flexible and intelligent data management.”
