|DISC > White Papers|
|discstor/nas HA: high availability & Clustering|
Up until very recently Network Attach Storage has been viewed as a mid-tier storage solution for the marketplace. Due to the overwhelming success of these often small and easy-to-use appliances, businesses were able to instantaneously add gigabytes of hard disk storage to their network in minutes.
At the same time that NAS technology was being adopted for its plug-n-play ease of use, enterprises were unable to efficiently leverage the technology due to its one-dimensional ability to store and serve files. Comparable storage technologies such as Storage Area Networks (SAN) were engineered from the very beginning to address needs concerning storage allocation, volume sets, partitioning and backup and redundancy. As the network storage market continues to mature however a combination of customer demand for the price and flexibility of NAS technology, with the robust features and redundancy of SAN are driving the market to deliver solutions that offer the best of both worlds.
DISCSTOR/nas High Availability is a network attach storage solution that combines complementary storage architectures to ensure that data will be available when needed. Evolving beyond the standard version of DISCSTOR/nas, the High Availability product employs clustering technology to meet the availability demands of the enterprise marketplace. DISCSTOR/nas HA is one of the most comprehensive storage solutions on the market today, and is one of the first products to offer the ease of use connectivity of NAS with the scalability and feature-set of optical storage technology
DISCSTOR/nas HA Features
DISCSTOR/nas HA employs a number of unique features that capitalize upon the inherent advantages of hard disk and optical storage to offer a self-backing and self-healing storage system which consists of mirrored library systems that appear on the network as a single device.
Redundancy & Clustering
Redundant, fault-tolerant storage is achieved by using clustered data storage and real-time archiving to optical storage. Clustering technology provides data security by using mirrored member systems that appear on the network as a single device under one IP address. Cluster members may be located either in close proximity to one another, or may be distributed across the network for security and logistics concerns, and are capable of real-time mirroring for both the hard disk and optical storage components.
Real-time archiving to optical storage works as an effective data backup method and allows for file versioning and data rollback functionality. The traditional methods of scheduled backups, or network snapshots, to magnetic tape leave data vulnerable until the actual process is completed. With DISCSTOR/nas HA the most current data file versions residing on the optical media can quickly and easily retrieved and restored.
During normal operation the DISCSTOR/nas HA system will monitor network health and will test the public, and private, networks for the ability of each member of the cluster to contact one another. In the event that a member node in the cluster fails, the surviving member continues to accept and store information. Once the affected member node has been repaired and brought online, it will connect to the surviving node. The affected node will then discover that the surviving node had previously failed, and will wait for the acting master to replicate changed data. Because optical storage technology is used for the archive component, the mirrored systems can be quickly re-synchronized by copying only the data that has been added to the surviving member to the failed member, thus reducing recovery time.
File System Journaling
Data integrity on the hard disk drive-based storage portion of DISCSTOR/nas HA is indexed using File System Journaling, a process which constantly updates, and backs up, the hard disk log files and recovers unsaved data. This feature ensures that in the event of a system failure, the data tables, links and configurations on the hard disk drive storage prior to the crash can be restored quickly and easily.
UDF File System
Data is written to the optical storage portion of the system using the UDF file system standard which was developed to achieve consistency amongst data written to various optical mediums. The real world application is that data written to optical media in DISCSTOR/nas can be physically exported out of the storage device, and read by popular storage system products on the market today, adding a dimension of instant portability to the solution.
DISCSTOR/nas HA is easily managed using standard browser-based utilities where configuration, storage hierarchy, shares, user quotas and cluster management settings are available from any Internet-accessible location.
DISCSTOR/nas HA provides redundant, clustered storage to ensure that data will be available when needed. Unique amongst clustered storage products on the market, DISCSTOR/nas HA is the only product which combines the characteristics of hard disk drive with the inherent reliability and portability of optical technology which results in a self-backing, self-healing storage and archive solution.