Whether you’re a seasoned IT expert or a relative newcomer, the jargon surrounding data storage technologies can be overwhelming. That’s why we’ve selected 10 of the most popular and useful data storage terms found on SearchStorage.com with the hope that you’ll never confuse "disk striping" with something done using a paint roller. If you’re already well-schooled on storage terms, check out the related material associated with each definition to read some advanced content on each topic.
Data storage term 1: Redundant array of independent disks (RAID)
This data protection method is the most popular way to simultaneously store data on multiple hard disks. The main advantage of RAID is that it allows I/O requests to overlap in a way that improves performance when having to copy one set of data to multiple locations.
Related material on RAID
- RAID levels and their pros and cons
- Comparing RAID price/performance
- Configuring RAID to your computing environment
Data storage term 2: Storage-area network (SAN)
A SAN is a high-speed, special-purpose network (or subnetwork) that interconnects different kinds of data storage devices with associated data servers on behalf of a larger network of users. A SAN supports special functions such as disk mirroring, backup and restore, archiving and data migration. Fibre Channel is the network protocol most often used for a storage-area network, although Ethernet protocols such as iSCSI have also become viable options for SANs.
Related material on SANs
- SAN connectivity between devices
- Storage-area network basics: What to look for before purchasing a SAN
- 10 reasons to upgrade to a SAN
Data storage term 3: Primary storage
Primary storage refers to storage for data in active use, in contrast to data used for backup or archiving purposes. Primary storage is used for the most frequently accessed data and typically consists of the most expensive storage tiers.
Related material on primary storage
- Tips on optimizing primary storage
- Using primary storage dedupe with virtual machines
- Options for primary storage data deduplication
Data storage term 4: Tiered storage
Based on levels of protection, performance needs, frequency of usage and other considerations, tiered storage technology assigns various types of data to different storage systems to achieve greater overall efficiency and performance. For example, tier 1 data (mission-critical, recently accessed or classified files) is typically stored on the highest performance drives available, while tier 2 data (infrequently used or less important data) might be located on less expensive hardware.
Related material on tiered storage
- Tips on tiering data storage
- Tiered storage strategies for the data center
- Flash SSD’s role in storage tiering
Data storage term 5: Network-attached storage (NAS)
Network-attached storage is an individual network set up around hard disk storage for files. Because NAS isn’t attached to the enterprise application server, storage access and management functions can be carried out at a separate location, allowing multiple computers and processors to handle program and storage requests separately. This results in greater overall I/O performance.
Related material on NAS
- Learn how to pick a NAS appliance
- The effect of scale-out architecture on NAS management
- Clustered and traditional NAS systems: What’s the difference?
Data storage term 6: Fibre Channel (FC)
Designed to provide high-speed connectivity between servers and storage devices, Fibre Channel connections can deliver speeds of 16 Gbps. Fibre Channel also offers support for devices up to six miles apart. Fibre Channel replaced the Small Computer System Interface (SCSI) protocol for storage networks.
Related material on Fibre Channel
- FC SANs in a virtual environment
- Pros and cons of Fibre Channel SAN zoning
- What you need to know about Fibre Channel SAN switches
Data storage term 7: Data deduplication
Data dedupe is a data reduction technology. It works by allowing duplicate data to be replaced with a pointer file that redirects applications to the original file stored in a single location. For example, a single 1 megabyte file can take the place of 100 copies of that same 1 megabyte file by substituting 99 pointer files, resulting in potentially enormous capacity savings. This technology is a popular way to reduce capacity requirements for functions like data backup and data archiving, and is emerging as a way to reduce the capacity of primary storage.
Related material on data deduplication
- Dedupe best practices
- Understanding dedupe ratios in backup systems
- Using data deduplication technology eases storage requirements
Data storage term 8: Disk striping
Disk striping technology divides data across multiple partitions and disks in computer systems. Striping speeds data retrieval, especially when many drives are used in a RAID scheme. Striping data across multiple hard disks improves performance because it uses hardware in all the drives in parallel. Wide striping spreads chunks of data across multiple arrays, while narrow striping uses a single array to spread data chunks.
Related material on disk striping
- Using striping technology in RAID systems
- Wide striping technology explained
- The advantages of doing a wide stripe with SSD storage
Data storage term 9: Logical unit number (LUN)
A logical unit number uniquely identifies hard disk devices for use with SCSI, iSCSI and Fibre Channel interfaces. LUNs are central to the management of block storage arrays shared over a storage-area network.
Related material on LUNs
- Tips for managing logical unit numbers
- How to maintain LUN performance
- Virtual and thin logical unit numbers explained
Data storage term 10: Storage virtualization
Storage virtualization pools data from multiple physical storage network devices into one virtual location, allowing for easier management and synchronized performance of functions like backup, archiving and recovery. Virtualization can be implemented using software only, appliances or in the storage array.
Related material on storage virtualization