Xtore™ Professional Storage

Glossary

RAID Level Characteristic Difference Usability
RAID 0 Uses Space Striping to combine multiple disk drives into one large volume. (One large virtual disk) There is no fault tolerance. No fault tolerance. If any of the disk drives fails, the whole volume will fail and all data will be lost. Provides data stripping (spreading out the blocks of each file across multiple disks) but no redundancy. This improves performance but does not deliver fault protection. It is a better disk array option for those who is constantly transmitting huge volumes of data (for example: a video streaming provider) due to the better transmits time and higher quality.
RAID 1 Uses disk Mirroring to keep a full backup of all information. Half of all the disks are used to hold a redundant copy of the data. There are two sets of disks both reading and writing at the same time. This provides the benefits of RAID 0 but also provides the security of full redundancy but at twice the cost. This type of RAID can ensure a high level of data security, but because it only has a 50% utilization rate, the cost is higher than other RAID types.
RAID 5 RAID 5 utilizes one of the multiple storage spaces to store redundancy information (parity), which enables data reconstruction in the event of a drive failure. Thus if there are n hard disk drives, the actual storage space for a RAID 5 system is equivalent to having only n-1 . RAID 5 provides a high level of data integrity and is more cost effective than RAID 1 because of the higher actual disk space availability. It is suggested to select RAID 5 in situation where there is a need for high level of data integrity, especially when it comes to the enterprise level.
RAID 5 (with Hot Spare) In this type of RAID, a spare hard disk is added to a RAID 5 volume for automatic space recovery. RAID 5 with Hot Spare uses one hard disk to store redundancy and keeps one extra disk empty as a spare. Thus if there are n hard disks, the actual space available is equivalent to having only n-2. If a hard disk fails or malfunctions, the spare hard disk space will be on-line and automatically replace the malfunctioned disk. Because online data rebuilding is available using the spare disk, this volume type can provide faster data reconstruction than RAID 5.
JBOD stands for "Just a Bunch Of Disk". This acronym is used to refer to hard disks that aren't configured according to RAID. (RAID is defined as a subsystem of disk drives that employ two or more drives in combination for fault tolerance and performance enhancement.
iSCSI is a young technology that promises simpler networks and lower costs because its based on the much more common Internet Protocol (IP). The key to this technology is the ability to speed up IP-specifically, the TCP/IP processing that packages data to be sent on the network. It supports Windows, Linux, Apple, and Novell platforms and has a lower cost than its rival – SAN. SAN is used with high-end networking equipment based on Fiber Channel, an expensive and complicated but functioning and improving networking standard. To a certain extent, the two technologies are appropriate for different uses but because fundamentally they do the same job, hardware and software makers as well as customers must bet one way or the other or accommodate both.
Most modern File Systems use journaling techniques borrowed from the database world to improve crash recovery. Disk transactions are written sequentially to an area of disk called the journal or log before being written to their final locations within the File System. Implementations vary in terms of what data is written to the log. Some implementations write only the File System metadata, while others record all writes to the journal.
SNMP stands for "Simple Network Management Protocol" and is part of the standard TCP/IP protocol. It was developed for managing complex network and it is possible to manage wiring HUBs, Toasters, or Jukeboxes by sending PDUs ( "Protocol Data Units" ) to different parts of the network or connected devices.
Most network security system operate by allowing selective use of services. An "Access Control List" is the usual means by which access to, and denial of, services is controlled. It is simply a list of services available and the associated hosts permitted to use the service.
File Locking is a file level security mechanism which bans the access rights for unauthorized users preventing them from accessing files. The current Filer version can only control share level security and will have similar functions at the file level in the next release.
This is a standards-based technology that enables groups to work together and share documents across the Internet or a local intranet. CIFS is designed to be cross-platform and runs over TCP/IP using the Internet's global Domain Naming Service.
This refers to storage (usually disk but possibly tapes or memory) attached to and distributed (shared) over a network. Usually the environment of a NAS is such that many computers share a lot of data in order to increase security while reducing maintenance and data management costs.
When you save a file to your hard disk, the operating system will try and store the complete content of the file to the same section of the hard disk. When the disk starts to become full, this goal becomes impossible to achieve and the operating system splits the contents of the file over different section of the disk. The file become fragmented and we call this File Fragmentation. When a user tries to access this file, an extra process is needed in order to gather the file fragments and join them to form the complete file.
Storage over IP uses the mainly standardized IP-Base protocol to connect to different storage devices and allow those devices to run under DAS, NAS, or SAN Infrastructures. The management of the network storage systems will allow the user to use End-to-End, Virtualization or Aggregation.
With NDMP, network congestion is minimized because the data path and control path are separated. Backups can occur locally from the file server directly to the tape drives, while management can occur from a centralized location. Furthermore, NDMP is an open-standard protocol promoted and supported by Server vendors, Backup software vendors, and Backup device vendors.
A SAN is a high performance and dedicated network storage subsystem that is connected to the backend of a server. A SAN Gateway liberates the devices, so they are not on any one particular server bus, and attaches them directly to the system network via network processors. The result is that SAN architecture makes all storage devices accessible to all servers on the network. However, to build up a SAN requires that Fiber Channel be used as the main structure, effectively making the cost considerably expensive. Regardless, many people believe that the SAN will become the standard Enterprise-wide network storage solution.
NIS is one of the Client/Server protocols developed by Sun Microsystems and is also referred to as Yellow Pages (YP). UNIX administrators to manage databases that are distributed across a network commonly use this service. Sun Microsystems authorizes this protocol to almost all the Unix system developers.
Defragmentation is a utility that use extra an Access Arm to scan the hard disk for fragmented files and puts the files back together.
1) The Network Filer Plus supports IDE HDD HOT SWAP.

2) The Network Filer Plus supports Multi-languages.

3) The Network Filer Plus supports RAID HOT SPARE in order to achieve on-line data re-building and avoid system Down Time.

4) The Network Filer Plus supports Network Trunking and Failover. When one of the Ethernet cards is down, the system will enable the backup Ethernet card to avoid disconnection.

5) The Network Filer Plus offers cross platform support.(Windows/UNIX/Apple/Novell…..etc.)

6) The Network Filer Plus supports all RAID and non-RAID standards.
RAID is the abbreviation of the acronym "Redundant Array of Independent Disks". A grouping of standard disk drives together with a RAID controller is used to create a storage device that acts as one disk to provide performance beyond that available from an individual disk. Primarily designed for operation with computers, RAID can offer very high capacity, fast data transfer rates, and much-increased security of data. The latter is achieved through disk redundancy so that disk errors or failures can be detected and corrected.