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Block-level Storage
Block-level storage is a concept in cloud-hosted data persistence where cloud services emulate the behaviour of a traditional block device, such as a physical hard drive. Storage in such services is organised as blocks. This emulates the type of behaviour seen in traditional disks or tape storage through storage virtualization. Blocks are identified by an arbitrary and assigned identifier by which they may be stored and retrieved, but this has no obvious meaning in terms of files or documents. A file system must be applied on top of the block-level storage to map 'files' onto a sequence of blocks. Amazon EBS (elastic block store) is an example of a cloud block store. Cloud block-level storage will usually offer facilities such as replication for reliability, or backup services. Block-level storage is in contrast to an object store or 'bucket store', such as Amazon S3 (simple storage service), or to a database. These operate at a higher level of abstraction and are able to wor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Persistent Data Structure
In computing, a persistent data structure or not ephemeral data structure is a data structure that always preserves the previous version of itself when it is modified. Such data structures are effectively immutable, as their operations do not (visibly) update the structure in-place, but instead always yield a new updated structure. The term was introduced in Driscoll, Sarnak, Sleator, and Tarjan's 1986 article. A data structure is partially persistent if all versions can be accessed but only the newest version can be modified. The data structure is fully persistent if every version can be both accessed and modified. If there is also a meld or merge operation that can create a new version from two previous versions, the data structure is called confluently persistent. Structures that are not persistent are called ''ephemeral''. These types of data structures are particularly common in logical and functional programming, as languages in those paradigms discourage (or fully forbid) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object Storage
Object storage (also known as object-based storage or blob storage) is a computer data storage approach that manages data as "blobs" or "objects", as opposed to other storage architectures like file systems, which manage data as a file hierarchy, and block storage, which manages data as blocks within sectors and tracks. Each object is typically associated with a variable amount of metadata, and a globally unique identifier. Object storage can be implemented at multiple levels, including the device level (object-storage device), the system level, and the interface level. In each case, object storage seeks to enable capabilities not addressed by other storage architectures, like interfaces that are directly programmable by the application, a namespace that can span multiple instances of physical hardware, and data-management functions like data replication and data distribution at object-level granularity. Object storage systems allow retention of massive amounts of unstructured data ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Storage Area Network
A storage area network (SAN) or storage network is a computer network which provides access to consolidated, block device, block-level data storage. SANs are primarily used to access Computer data storage, data storage devices, such as disk arrays and tape libraries from Server (computing), servers so that the devices appear to the operating system as direct-attached storage. A SAN typically is a dedicated network of storage devices not accessible through the local area network (LAN). Although a SAN provides only block-level access, file systems built on top of SANs do provide file-level access and are known as shared-disk file systems. Newer SAN configurations enable hybrid SAN and allow traditional block storage that appears as local storage but also object storage for web services through APIs. Storage architectures Storage area networks (SANs) are sometimes referred to as ''network behind the servers'' and historically developed out of a centralized data storage mode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-RAID Drive Architectures
The most widespread standard for configuring multiple hard disk drives is RAID (redundant array of inexpensive/independent disks), which comes in a number of standard configurations and non-standard configurations. Non-RAID drive architectures also exist, and are referred to by acronyms with tongue-in-cheek similarity to RAID: * JBOD (just a bunch of disks): described multiple hard disk drives operated as individual independent hard disk drives. * SPAN or BIG: A method of combining the free space on multiple hard disk drives from "JBoD" to create a spanned volume. Such a concatenation is sometimes also called BIG/SPAN. A SPAN or BIG is generally a spanned volume only, as it often contains mismatched types and sizes of hard disk drives. * MAID (massive array of idle drives): an architecture using hundreds to thousands of hard disk drives for providing nearline storage of data, primarily designed for write once, read occasionally (WORO) applications, in which increased storage den ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Storage Area Network
A storage area network (SAN) or storage network is a computer network which provides access to consolidated, block device, block-level data storage. SANs are primarily used to access Computer data storage, data storage devices, such as disk arrays and tape libraries from Server (computing), servers so that the devices appear to the operating system as direct-attached storage. A SAN typically is a dedicated network of storage devices not accessible through the local area network (LAN). Although a SAN provides only block-level access, file systems built on top of SANs do provide file-level access and are known as shared-disk file systems. Newer SAN configurations enable hybrid SAN and allow traditional block storage that appears as local storage but also object storage for web services through APIs. Storage architectures Storage area networks (SANs) are sometimes referred to as ''network behind the servers'' and historically developed out of a centralized data storage mode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virtual Machine
In computing, a virtual machine (VM) is the virtualization or emulator, emulation of a computer system. Virtual machines are based on computer architectures and provide the functionality of a physical computer. Their implementations may involve specialized hardware, software, or a combination of the two. Virtual machines differ and are organized by their function, shown here: * ''System virtual machines'' (also called full virtualization VMs, or SysVMs) provide a substitute for a real machine. They provide the functionality needed to execute entire operating systems. A hypervisor uses native code, native execution to share and manage hardware, allowing for multiple environments that are isolated from one another yet exist on the same physical machine. Modern hypervisors use hardware-assisted virtualization, with virtualization-specific hardware features on the host CPUs providing assistance to hypervisors. * ''Process virtual machines'' are designed to execute computer programs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amazon Elastic Compute Cloud
Amazon Elastic Compute Cloud (EC2) is a part of Amazon's cloud-computing platform, Amazon Web Services (AWS), that allows users to rent virtual computers on which to run their own computer applications. EC2 encourages scalable deployment of applications by providing a web service through which a user can boot an Amazon Machine Image (AMI) to configure a virtual machine, which Amazon calls an "instance", containing any software desired. A user can create, launch, and terminate server-instances as needed, paying by the second for active servershence the term "elastic". EC2 provides users with control over the geographical location of instances that allows for latency optimization and high levels of redundancy. In November 2010, Amazon switched its own retail website platform to EC2 and AWS. History Amazon announced a limited public beta test of EC2 on August 25, 2006, offering access on a first-come, first-served basis. Amazon added two new instance types (Large and Extra-La ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amazon S3
Amazon Simple Storage Service (S3) is a service offered by Amazon Web Services (AWS) that provides object storage through a web service interface. Amazon S3 uses the same scalable storage infrastructure that Amazon.com uses to run its e-commerce network. Amazon S3 can store any type of object, which allows uses like storage for Internet applications, backups, disaster recovery, data archives, data lakes for analytics, and hybrid cloud storage. AWS launched Amazon S3 in the United States on March 14, 2006, then in Europe in November 2007. Technical details Design Amazon S3 manages data with an object storage architecture which aims to provide scalability, high availability, and low latency with high durability. The basic storage units of Amazon S3 are objects which are organized into buckets. Each object is identified by a unique, user-assigned key. Buckets can be managed using the console provided by Amazon S3, programmatically with the AWS SDK, or the REST application ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amazon Elastic Block Store
Amazon Elastic Block Store (EBS) provides raw block-level storage that can be attached to Amazon EC2 instances and is used by Amazon Relational Database Service (RDS). It is one of the two block-storage options offered by AWS, with the other being the EC2 Instance Store. Amazon EBS provides a range of options for storage performance and cost. These options are divided into two major categories: SSD-backed storage for transactional workloads, such as databases and boot volumes (performance depends primarily on IOPS), and disk-backed storage for throughput intensive workloads, such as MapReduce and log processing (performance depends primarily on MB/s). Use case In a typical use case, using EBS would include formatting the device with a filesystem and mounting it. EBS supports advanced storage features, including snapshotting and cloning. As of September 2020, EBS volumes can be up to 2 TiB in size using the MBR partitioning scheme, and up to 16 TiB using the GPT partitio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloud Computing
Cloud computing is "a paradigm for enabling network access to a scalable and elastic pool of shareable physical or virtual resources with self-service provisioning and administration on-demand," according to International Organization for Standardization, ISO. Essential characteristics In 2011, the National Institute of Standards and Technology (NIST) identified five "essential characteristics" for cloud systems. Below are the exact definitions according to NIST: * On-demand self-service: "A consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with each service provider." * Broad network access: "Capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, tablets, laptops, and workstations)." * Pooling (resource management), Resource pooling: " The provider' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Storage Virtualization
In computer science, storage virtualization is "the process of presenting a logical view of the physical storage resources to" a host computer system, "treating all storage media (hard disk, optical disk, tape, etc.) in the enterprise as a single pool of storage." A "storage system" is also known as a storage array, disk array, or ''filer''. Storage systems typically use special hardware and software along with disk drives in order to provide very fast and reliable storage for computing and data processing. Storage systems are complex, and may be thought of as a special purpose computer designed to provide storage capacity along with advanced data protection features. Disk drives are only one element within a storage system, along with hardware and special purpose embedded software within the system. Storage systems can provide either block accessed storage, or file accessed storage. Block access is typically delivered over Fibre Channel, iSCSI, SAS, FICON or other prot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
