What is Tiered Storage?
Tiered Storage is a storage networking technique where data storage is carried out on various types of media based on price, performance, availability and recovery attributes. This is to ensure that data which is intended for restoration during data loss or data corruption can be available locally for fast recovery, while the data which may be useful for future uses could be archived on low cost media to lower the functional costs.
In order to better understand better the concept of Tiered Storage here is a paradigm. Mission critical data which is frequently in access has to be stored on expensive and high quality media such as Flash. This ensures that the data availability will be quick and so there will be no situation related to downtime. The data can also be stored on double parity RAID or redundant array of independent disks in order to have fault tolerance and redundancy.
Similarly, data which is seldom in use is stored in less expensive media in the traditional Storage Area Network (SAN). As the number of tiers increase, cheaper media is deployed to use and thus tier three can contain data which is event driven or rarely used or has unclassified files, which can be recorded onto compact disks or tape or tape libraries.
In today’s modern infrastructure related to storage, Tiered storage architecture can range from a simple two tier architecture which may consist of SCSI or Fibre Channel attached disk and tape storage. In the event of more complex infrastructure it may comprise of five to six or maximum ten tiers. It is a fact that, regardless of number of tiers, organizations are looking for tiered storage which can be obtained at lower functional costs and can improve operational efficiency.
The cost associated with achieving of RTO and RPO close to zero can be done with the implementation of Tiered Storage Infrastructure. Based on applications and business requirements, the data can be classified in order to provide different RPOs and RTOs. Meanwhile, policy based data migration also guarantees that the precise data is in the correct place at right time.
Since, assigning data to different tier levels can be a complex activity, automated tiered storage software can be deployed in this event. By means of Automated Tiered Storage software an automated progression or demotion of data across different tiers or storage media can take place. This auto migration of data on different storage media will be based on performance and capacity requirements.