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List Of Log-structured File Systems
This is an incomplete list of log-structured file system implementations. * James T, Brady while in IBM Poughkeepsie Lab conceived a log structured paging file system in 1979 which was implemented in MVS SP2 in 1980."1981 IBM Corporate Technical Recognition Event Book, Outstanding Innovation Award, “Virtual Storage Disk Paging”" * John K. Ousterhout and Mendel Rosenblum implemented the first log-structured file system for the Sprite operating system in 1992.Rosenblum, Mendel and Ousterhout, John K. (June 1990) -The LFS Storage Manager. ''Proceedings of the 1990 Summer Usenix''. pp315-324.Rosenblum, Mendel and Ousterhout, John K. (February 1992) -. ''ACM Transactions on Computer Systems, Vol. 10 Issue 1''. pp26-52. * BSD-LFS, an implementation by Margo Seltzer was added to 4.4BSD, and was later ported to 386BSD. It lacked support for snapshots. It was removed from FreeBSD and OpenBSD, but still lives on in NetBSD. * Plan 9's Fossil file system is also log-structured and supp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Log-structured File System
A log-structured filesystem is a file system in which data and metadata are written sequentially to a circular buffer, called a log. The design was first proposed in 1988 by John K. Ousterhout and Fred Douglis and first implemented in 1992 by Ousterhout and Mendel Rosenblum for the Unix-like Sprite distributed operating system. Rationale Conventional file systems tend to lay out files with great care for spatial locality and make in-place changes to their data structures in order to perform well on optical and magnetic disks, which tend to seek relatively slowly. The design of log-structured file systems is based on the hypothesis that this will no longer be effective because ever-increasing memory sizes on modern computers would lead to I/O becoming write-heavy because reads would be almost always satisfied from memory cache. A log-structured file system thus treats its storage as a circular log and writes sequentially to the head of the log. This has several important s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NetApp
NetApp, Inc. is an American hybrid cloud data services and data management company headquartered in San Jose, California. It has ranked in the Fortune 500 from 2012–2021. Founded in 1992 with an IPO in 1995, NetApp offers cloud data services for management of applications and data both online and physically. History NetApp was founded in 1992 by David Hitz, James Lau, and Michael Malcolm as Network Appliance, Inc. At the time, its major competitor was Auspex Systems. In 1994, NetApp received venture capital funding from Sequoia Capital. It had its initial public offering in 1995. NetApp thrived in the internet bubble years of the mid 1990s to 2001, during which the company grew to $1 billion in annual revenue. After the bubble burst, NetApp's revenues quickly declined to $800 million in its fiscal year 2002. Since then, the company's revenue has steadily climbed. In 2006, NetApp sold the NetCache product line to Blue Coat Systems. In 2008, Network Appliance o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD-RW
CD-RW (Compact Disc-Rewritable) is a digital optical disc storage format introduced in 1997. A CD-RW compact disc (CD-RWs) can be written, read, erased, and re-written. CD-RWs, as opposed to CDs, require specialized readers that have sensitive laser optics. Consequently, CD-RWs cannot be read in many CD readers built prior to the introduction of CD-RW. CD-ROM drives with a "MultiRead" certification are compatible. CD-RWs must be erased or blanked before reuse. Erasure methods include full blanking where the entire surface of the disc is erased and fast blanking where only metadata areas, such as PMA, TOC and pregap, are cleared. Fast blanking is quicker and usually sufficient to allow rewriting the disc. Full blanking removes all traces of the previous data, and is often used for confidentiality purposes. CD-RWs can sustain fewer re-writes compared to other storage media (ca. 1,000 compared up to 100,000). Ideal use is for test discs (e.g. for CD authoring), temporary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flash Memory
Flash memory is an electronic non-volatile computer memory storage medium that can be electrically erased and reprogrammed. The two main types of flash memory, NOR flash and NAND flash, are named for the NOR and NAND logic gates. Both use the same cell design, consisting of floating gate MOSFETs. They differ at the circuit level depending on whether the state of the bit line or word lines is pulled high or low: in NAND flash, the relationship between the bit line and the word lines resembles a NAND gate; in NOR flash, it resembles a NOR gate. Flash memory, a type of floating-gate memory, was invented at Toshiba in 1980 and is based on EEPROM technology. Toshiba began marketing flash memory in 1987. EPROMs had to be erased completely before they could be rewritten. NAND flash memory, however, may be erased, written, and read in blocks (or pages), which generally are much smaller than the entire device. NOR flash memory allows a single machine word to be written to an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OpenVMS
OpenVMS, often referred to as just VMS, is a multi-user, multiprocessing and virtual memory-based operating system. It is designed to support time-sharing, batch processing, transaction processing and workstation applications. Customers using OpenVMS include banks and financial services, hospitals and healthcare, telecommunications operators, network information services, and industrial manufacturers. During the 1990s and 2000s, there were approximately half a million VMS systems in operation worldwide. It was first announced by Digital Equipment Corporation (DEC) as VAX/VMS (''Virtual Address eXtension/Virtual Memory System'') alongside the VAX-11/780 minicomputer in 1977. OpenVMS has subsequently been ported to run on DEC Alpha systems, the Itanium-based HPE Integrity Servers, and select x86-64 hardware and hypervisors. Since 2014, OpenVMS is developed and supported by VMS Software Inc. (VSI). OpenVMS offers high availability through computer cluster, clustering — the ability ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Equipment Corporation
Digital Equipment Corporation (DEC ), using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president until forced to resign in 1992, after the company had gone into precipitous decline. The company produced many different product lines over its history. It is best known for the work in the minicomputer market starting in the mid-1960s. The company produced a series of machines known as the PDP line, with the PDP-8 and PDP-11 being among the most successful minis in history. Their success was only surpassed by another DEC product, the late-1970s VAX "supermini" systems that were designed to replace the PDP-11. Although a number of competitors had successfully competed with Digital through the 1970s, the VAX cemented the company's place as a leading vendor in the computer space. As microcomputers improved in the late 1980s, especially wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3D XPoint
3D XPoint (pronounced ''three-D cross point'') is a discontinued non-volatile memory (NVM) technology developed jointly by Intel and Micron Technology. It was announced in July 2015 and is available on the open market under the brand name Optane (Intel) from April 2017 until July 2022. Bit storage is based on a change of bulk Electrical resistance, resistance, in conjunction with a stackable cross-grid data access array. Initial prices are less than dynamic random-access memory (DRAM) but more than flash memory. As a non-volatile memory, 3D XPoint has a number of features that distinguish it from other currently available Random-access memory, RAM and NVRAM. Although the first generations of 3D XPoint were not especially large or fast, as of 2019 3D XPoint is used to create some of the fastest SSDs available, with small-write CAS latency, latency. As the memory is inherently fast, and byte-addressable, techniques such as read-modify-write and Cache (computing), caching used to en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-volatile Dual In-line Memory Module
A NVDIMM (pronounced "en-vee-dimm") or non-volatile DIMM is a type of persistent random-access memory for computers using widely used DIMM form-factors. Non-volatile memory is memory that retains its contents even when electrical power is removed, for example from an unexpected power loss, system crash, or normal shutdown. Properly used, NVDIMMs can improve application performance and system crash recovery time. They enhance solid-state drive (SSD) endurance and reliability. Many "non-volatile" products use volatile memory during normal operation and dump the contents into non-volatile memory if the power fails, using an on-board backup power source. Volatile memory is faster than non-volatile; it is byte-addressable; and it can be written to arbitrarily, without concerns about wear and device lifespan. However, including a second memory to achieve non-volatility (and the on-board backup power source) increases the product cost compared to volatile memory. There are many emergi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Persistent Memory
In computer science, persistent memory is any method or apparatus for efficiently storing data structures such that they can continue to be accessed using memory instructions or memory APIs even after the end of the process that created or last modified them. Often confused with non-volatile random-access memory (NVRAM), persistent memory is instead more closely linked to the concept of persistence in its emphasis on program state that exists outside the fault zone of the process that created it. (A process is a program under execution. The fault zone of a process is that subset of program state which could be corrupted by the process continuing to execute after incurring a fault, for instance due to an unreliable component used in the computer executing the program.) Efficient, memory-like access is the defining characteristic of persistent memory. It can be provided using microprocessor memory instructions, such as load and store. It can also be provided using APIs that implem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NOVA (filesystem)
The NOVA (''non-volatile memory accelerated'') file system is an open-source, log-structured file system for byte-addressable persistent memory (for example non-volatile dual in-line memory module (NVDIMM) and 3D XPoint DIMMs) for Linux. NOVA is designed specifically for byte-addressable persistent memories and aims to provide high-performance, atomic file and metadata operations, and fault tolerance. To meet these goals NOVA combines several techniques found in other file systems. NOVA uses log structure, copy-on-write (COW), journaling, and log-structured metadata updates to provide strong atomicity guarantees, and it uses a combination replication, metadata checksums, and RAID 4 parity to protect data and metadata from media errors and software bugs. It also supports checkpoints to facilitate backups. Filesystem NOVA was developed at the University of California, San Diego, in the Non-Volatile Systems Laboratory of the Computer Science and Engineering Department. Patches we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ObjectiveFS
ObjectiveFS is a distributed file system developed by Objective Security Corp. It is a POSIX-compliant file system built with an object store backend.Christophe Bard"LeMagIT: ObjectiveFS: a POSIX file system on top of S3 (original article in French)" LeMagIT, 3 December 2014.Andrea Maur"ITPT 14 Report - ObjectiveFS" vInfrastructure Blog, 15 December 2014. It was initially released with AWS S3 backend, and has later implemented support for Google Cloud Storage and object store devices. It was released for beta in early 2013, and the first version was officially released on August 11, 2013. Design ObjectiveFS implements a log structured file system on top of object stores (such as Amazon S3, Google Cloud Storage and other object store devices). It is a POSIX compliant file system and supports features such as dynamic file system size, soft and hard links, unix attributes, extended attributes, Unix timestamps, users and permissions, no limit on file size, atomic renames, atomic fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nimble Storage
Nimble Storage, founded in 2008, produced hardware and software products for data storage, specifically data storage arrays that use the iSCSI and Fibre Channel protocols and includes data backup and data protection features. Nimble is now a subsidiary of Hewlett Packard Enterprise. History Nimble Storage was founded in January 2008 by Varun Mehta and Umesh Maheshwari. Nimble announced its first product, the CS200 series hybrid arrays, in July 2010 at Tech Field Day. In September 2012, Nimble Storage secured $40.7 million from original backers as well as new investors Artis Capital Management and GGV Capital. Varun Mehta was chief executive until March 2011, when he became vice president of engineering and Suresh Vasudevan became CEO. Umesh Maheshwari became chief technology officer. In October 2013 the company filed for its initial public offering on the New York Stock Exchange. Nimble Storage went public on the NYSE on December 13, 2013, under the ticker symbol NMBL. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
