System Fault Tolerance

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In computing, System Fault Tolerance (SFT) is a fault tolerant system built into NetWare operating systems. Three levels of fault tolerance exist:

Computing activity requiring, benefiting from, or creating computers

Computing is any activity that uses computers. It includes developing hardware and software, and using computers to manage and process information, communicate and entertain. Computing is a critically important, integral component of modern industrial technology. Major computing disciplines include computer engineering, software engineering, computer science, information systems, and information technology.

NetWare is a discontinued computer network operating system developed by Novell, Inc. It initially used cooperative multitasking to run various services on a personal computer, using the IPX network protocol.

Operating system collection of software that manages computer hardware resources

An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs.

Disk mirroring replication of logical disk volumes onto separate physical hard disks in real time to ensure continuous availability

In data storage, disk mirroring is the replication of logical disk volumes onto separate physical hard disks in real time to ensure continuous availability. It is most commonly used in RAID 1. A mirrored volume is a complete logical representation of separate volume copies.

RAID is a data storage virtualization technology that combines multiple physical disk drive components into one or more logical units for the purposes of data redundancy, performance improvement, or both. This was in contrast to the previous concept of highly reliable mainframe disk drives referred to as "single large expensive disk" (SLED).

Redundancy (engineering) Duplication of critical components to increase reliability of a system

In engineering, redundancy is the duplication of critical components or functions of a system with the intention of increasing reliability of the system, usually in the form of a backup or fail-safe, or to improve actual system performance, such as in the case of GNSS receivers, or multi-threaded computer processing.

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SCSI set of standards for physically connecting and transferring data between computers and peripheral devices

Small Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, electrical, optical and logical interfaces. SCSI is most commonly used for hard disk drives and tape drives, but it can connect a wide range of other devices, including scanners and CD drives, although not all controllers can handle all devices. The SCSI standard defines command sets for specific peripheral device types; the presence of "unknown" as one of these types means that in theory it can be used as an interface to almost any device, but the standard is highly pragmatic and addressed toward commercial requirements.

Network-attached storage computer data storage server

Network-attached storage (NAS) is a file-level computer data storage server connected to a computer network providing data access to a heterogeneous group of clients. NAS is specialized for serving files either by its hardware, software, or configuration. It is often manufactured as a computer appliance – a purpose-built specialized computer. NAS systems are networked appliances which contain one or more storage drives, often arranged into logical, redundant storage containers or RAID. Network-attached storage removes the responsibility of file serving from other servers on the network. They typically provide access to files using network file sharing protocols such as NFS, SMB, or AFP. From the mid-1990s, NAS devices began gaining popularity as a convenient method of sharing files among multiple computers. Potential benefits of dedicated network-attached storage, compared to general-purpose servers also serving files, include faster data access, easier administration, and simple configuration.

NetApp company

NetApp, Inc. is a hybrid cloud data services and data management company headquartered in Sunnyvale, California. It has ranked in the Fortune 500 since 2012. Founded in 1992 with an IPO in 1995, NetApp offers hybrid cloud data services for management of applications and data across cloud and on-premises environments.

The Write Anywhere File Layout (WAFL) is a file layout that supports large, high-performance RAID arrays, quick restarts without lengthy consistency checks in the event of a crash or power failure, and growing the filesystems size quickly. It was designed by NetApp for use in its storage appliances like NetApp FAS, AFF, Cloud Volumes ONTAP and ONTAP Select.

In computing, a NetWare File System (NWFS) is a file system based on a heavily modified version of FAT. It was used in the Novell NetWare operating system. It is the default and only file system for all volumes in versions 2.x through 4.x, and the default and only file system for the SYS volume continuing through version 5.x. Novell developed two varieties of NWFS:

  1. 16-bit NWFS 286, used in NetWare 2.x
  2. 32-bit NWFS 386, used in NetWare 3.x through NetWare 6.x.

Replication in computing involves sharing information so as to ensure consistency between redundant resources, such as software or hardware components, to improve reliability, fault-tolerance, or accessibility.

In computer storage, a NetApp "filer" is a storage system product by NetApp, before block protocols were supported. While it can serve storage over a network using file-based protocols such as NFS and SMB, the so-called "Filers" can also serve data over block-based protocol, such as the SCSI command protocol over the Fibre Channel Protocol on a Fibre Channel network, Fibre Channel over Ethernet (FCoE), FC-NVMe or iSCSI transport layer.

An incremental backup is one in which successive copies of the data contain only the portion that has changed since the preceding backup copy was made. When a full recovery is needed, the restoration process would need the last full backup plus all the incremental backups until the point of restoration. Incremental backups are often desirable as they reduce storage space usage, and are quicker to perform than differential backups.

Nested RAID levels, also known as hybrid RAID, combine two or more of the standard RAID levels to gain performance, additional redundancy or both, as a result of combining properties of different standard RAID layouts.

Although all RAID implementations differ from the specification to some extent, some companies and open-source projects have developed non-standard RAID implementations that differ substantially from the standard. Additionally, there are non-RAID drive architectures, providing configurations of multiple hard drives not referred to by RAID acronyms.

A clustered file system is a file system which is shared by being simultaneously mounted on multiple servers. There are several approaches to clustering, most of which do not employ a clustered file system. Clustered file systems can provide features like location-independent addressing and redundancy which improve reliability or reduce the complexity of the other parts of the cluster. Parallel file systems are a type of clustered file system that spread data across multiple storage nodes, usually for redundancy or performance.

NonStop Clusters (NSC) was an add-on package for SCO UnixWare that allowed creation of fault-tolerant single-system image clusters of machines running UnixWare. NSC was one of the first commercially available highly available clustering solutions for commodity hardware.

Storage area network network which provides access to consolidated, block level data storage

A storage area network (SAN) or storage network is a Computer network which provides access to consolidated, block level data storage. SANs are primarily used to enhance accessibility of storage devices, such as disk arrays and tape libraries, to servers so that the devices appear to the operating system as locally attached devices. A SAN typically is a dedicated network of storage devices not accessible through the local area network (LAN) by other devices, thereby preventing interference of LAN traffic in data transfer.

Universal Storage Platform (USP) was the brand name for an Hitachi Data Systems line of computer data storage disk arrays circa 2004 to 2010.

NetVault is a set of data protection software developed and supported by Quest Software. NetVault Backup is a backup and recovery software product. It can be used to protect data and software applications in physical and virtual environments from one central management interface. It supports many servers, application platforms, and protocols such as UNIX, Linux, Microsoft Windows, VMware, Microsoft Hyper-V, Oracle, Sybase, Microsoft SQL Server, NDMP, Oracle ACSLS, IBM DAS/ACI, Microsoft Exchange Server, DB2, and Teradata.

Resilient File System (ReFS), codenamed "Protogon", is a Microsoft proprietary file system introduced with Windows Server 2012 with the intent of becoming the "next generation" file system after NTFS.

References

Novell NetWare 4.2 documentation