Tertiary storage or tertiary memory refers to a data storage tier in which data is stored long-term and is not directly accessible by the computer’s CPU. While secondary storage is already one step removed from primary storage in terms of accessibility, tertiary storage is even further removed and is used for data that is accessed infrequently. Tertiary storage devices are often used in environments where vast amounts of data need to be archived.
Common Types of Tertiary Storage:
Robotic Tape Libraries:
- Automated systems that contain multiple tape drives and slots for holding tape cartridges. A robotic arm mechanism moves tapes between the drives and storage slots. These libraries can store vast amounts of data and are often used for backups and data archiving in enterprises.
Optical Jukeboxes:
- Similar to robotic tape libraries, but they store data on optical discs (like CDs or DVDs) rather than tapes. A robotic mechanism is used to pick and place discs in drives for reading or writing.
Offline Storage:
- This refers to storage media that is not online or connected to the computer unless the data is being recalled. Examples include tapes or discs that are stored on shelves until they are needed.
Characteristics of Tertiary Storage:
- Automated Retrieval: Given the sheer volume of data in these storage systems, a robotic mechanism is often employed to locate and retrieve data.
- Slow Access Times: Accessing data from tertiary storage is generally slower than from primary or secondary storage. The data first needs to be loaded or mounted, which can be time-consuming.
- High Capacity: Tertiary storage solutions are designed to hold vast amounts of data, often spanning petabytes.
- Cost-Effective: Per unit of data, tertiary storage tends to be more cost-effective than secondary storage, making it suitable for archiving.
- Infrequent Access: Data stored in tertiary storage is not accessed frequently. It’s often used for archiving and long-term backups.
- Data Redundancy: Given the importance of the data, tertiary storage systems often have built-in redundancy to protect against data loss.
Importance:
- Long-term Data Preservation: Essential for businesses and institutions that need to retain data for extended periods, whether for compliance, historical, or backup purposes.
- Scalability: Tertiary storage systems can be expanded to accommodate growing data needs.
- Disaster Recovery: Having backups in tertiary storage can be crucial for data recovery in case of disasters or data corruption in primary or secondary storage.
- Cost Savings: Storing data in tertiary storage can be more cost-effective than keeping everything in primary or secondary storage, especially when considering the total cost of ownership.
In conclusion, while tertiary storage might not be as immediately accessible as primary or secondary storage, it plays a crucial role in comprehensive data management strategies, especially for large enterprises, research institutions, and organizations with significant data archiving needs.