What is Nearline Backup? What is the difference between NearStore and NearStore?

The so-called near-line storage (NearStore), is with the customer storage environment of the refinement of a concept put forward, the so-called near-line storage, the extension is relatively broad, mainly located in the customer online storage and offline storage between the application. That is to say, the data that is not often used, or the data access is not large in the lower performance of the storage device. But at the same time for these devices is required to address quickly, high transfer rate. (e.g., the archiving of some of the customer's long-held files that are not used for long periods of time). As a result, near-line storage has relatively low performance requirements, but requires relatively good access performance. At the same time, in most cases, because of the infrequent data to account for a relatively large proportion of the total data volume, which also requires near-line storage devices in the need for relatively large capacity.

When doing hierarchical storage, there will be data migration. But performing data migration is not necessarily hierarchical storage.

Comparing online, nearline, and offline storage

Traditionally, there are two ways to store data: online storage and offline storage.

Online storage means that the storage device and the stored data remain "online" at all times and can be read at will by the user to meet the data access speed requirements of the computing platform. Just like the disk storage mode commonly used in PCs. Generally online storage devices such as disks and disk arrays are relatively expensive, but have better performance.

Offline storage is a backup of data stored online to protect against possible data disasters. The data stored offline is not often called upon and is generally far from system applications, so the term "offline" is used to vividly describe this type of storage.

Data on offline storage media is read and written sequentially. When data needs to be read, the tape is spooled to the beginning and then positioned. When changes need to be made to the data that has been written, all of the data needs to be rewritten in its entirety. As a result, offline storage is slow and inefficient to access. A typical product for offline storage is a tape library, which is relatively inexpensive.

The so-called near-line storage (NearStore), with the refinement of the customer's storage environment proposed a concept, the so-called near-line storage, the extension of the relatively broader, is mainly located in the customer online storage and offline storage between the application. That is to say, the data that is not often used, or the data access is not large in the lower performance of the storage device. But at the same time the requirements for these devices is rapid addressing, high transfer rate. (For example, the customer some long-term preservation of not long used file archiving). As a result, near-line storage has relatively low performance requirements, but requires relatively good access performance. At the same time, in most cases, due to the infrequent data to account for a relatively large proportion of the total amount of data, which also requires near-line storage devices in the need for relatively large capacity.