When it comes to long-term archiving of digital information, there are several media choices, including tape, optical media, NAS, SAN, and object storage.
Tape: Old standby
Tape is a traditional solution for backup and archiving needs and has been in use for many years. For long-term storage, it can seem at first blush to be a cost-effective solution when compared with disk-based storage.
However, once you look at the logistics surrounding growing tape libraries and the long-term costs of those environments, the advantage isn't so clear. In terms of reliability, IT managers say that a disturbingly high percentage of tape restores fail. Of course, the disadvantages of sequential access to information on tape means that recovery times can be long and rapid direct access to specific information is impossible.
Optical: Failure rate debate
Optical media has the portability of tape, but it doesn't have the same capacity. One clear advantage of optical is direct access for quicker restores, but because of the nature of removable media, it doesn't provide online access.
The management and handling challenges of growing optical backup libraries are not that different from tape, and with comparatively higher media cost, TCO of optical systems is similar. Failure rates for optical media have been the subject of a lot of debate and study. Higher capacity Blu-ray media may be more susceptible to environmental stress.
NAS and SAN: Access and protection
When it comes to performance for information access, network attached storage solutions NAS and SAN are great. Archived files can be quickly searched, and specific information can be restored without having to wait for a tape to spin.
Importantly, NAS and SAN solutions bring data protection to the table like RAID protection to prevent physical media issues from causing data loss. The reality is that storage solutions are designed for primary storage and can be expensive.
Automated tiering solutions can definitely lower the $/MB. Traditional NAS system namespaces are limited, preventing growth past preset limits. Archiving solutions for some applications, such as banking and healthcare, need to prove the integrity of their archives and require data immutability assurance that may not be available in SAN and NAS systems.
Object storage: Think efficient
For digital archiving, object storage systems are a great solution. They don't have the transactional performance of SAN or NAS, but they have the online data accessibility of primary storage systems.
They are designed to be easy to manage and provide data protection not afforded in tape solutions. By their nature, object stores don't have the namespace limitations of NAS storage, and so can scale to very large capacities.
For some applications, immutability must be assured and write-once/read-many (WORM) capabilities are a feature of many object storage systems. Storage of rich metadata on stored objects enables the application of management policies to govern the features of the storage, which is great for archival applications. For example, object storage systems can use metadata to automatically administer per-object data management policies, like number of replicas or destruction date. Redundant Array of Independent Nodes (RAIN) is the name of the technique of replicating data to other nodes within the object storage system to enhance reliability.
The right implementation of object storage offers a space and energy-efficient dense storage solution. A scale-out architecture using commodity hardware allows for a cost-effective solution that can start small can grow over time as needed.
The intelligence built into the software running the object storage system allows for a less-complex-to-manage system. This approach provides a measureable boost in enterprise efficiency and can be truly seen as the next phase in archiving solutions.