It seems there is still some confusion out there on how, when, where and why to tier internal storage, so I’ll take a shot at explaining this as I know it today. The easiest and most sensible place to start is of course at the “Why” tier my storage. As with everything in the business world today, the why is focused on “efficiency”. Tiering storage in data centers is popular because storage tiering ensures you are maximizing your storage price/performance. For instance, the upper tiers or primary storage (Tier 0 & 1) demand the highest performance and thus command the highest price tag. It’s commonly used for the hottest and most frequently used data while the bottom tiers, secondary or bulk storage (Tier 2 & 3) is relegated to less frequently accessed data that is stored on less expensive (lowest $/GB) capacity-optimized storage.
Moving on to “where and how” to store your data, it’s a good idea to rate the application usage within your organization. Here are some general guidelines that may prove useful.
HOT DATA: Up until last year, hot data was typically stored on Tier 1 hard disk drives – namely 10K and 15K-RPM spinning media. Today, some of the hottest of that hot data (Tier 0) has been moved to an SSD (Solid State Disk) for instantaneous access.
WARM DATA: When its data that needs to be read and/or written to often and is critically important to the organization, this Tier 1 data is often stored on mainstream 10K and 15K-RPM hard drives. Much more affordable than SSDs, these drives offer the highest form of reliable, consistent performance for high demand applications.
COOL DATA: The biggest pool of data is stored in Tier 2 primarily because of its cost-efficiency. Offering high capacity storage at the most economical $/GB, this is where the data that must be readily available on-line yet is not critically vital to the organization today is stored.
COLD DATA: Data at rest or archived data has traditionally been stored on tape. As the cost of hard drives has declined and the blurring between on-line and off-line access requirements has occurred, some data centers are opting for using high capacity, low power hard drives for their cold storage requirements.
And now for the “when”. Obviously, data storage is a constant and essential component for successful businesses today and data growth is expanding exponentially year upon year. In fact, staying ahead of the storage demand can be an exhaustive and painful effort. But as we know, what’s hot today probably won’t be hot tomorrow, so storage tiering allows you to move data easily between these tiers making you as efficient as possible. Auto Storage Tiering (AST) will make your life easier. Storage magazine’s recent “Storage Purchasing Intentions Survey” found 27% of data storage managers currently use automated storage tiering (AST) and another 32% will evaluate the technology.
Are you tiering your storage today? If so, how many tiers of storage do you have? And if not, what’s holding you back?