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F2fs
F2FS (Flash-Friendly File System) is a flash file system initially developed by Samsung Electronics for the Linux kernel. The motive for F2FS was to build a file system that, from the start, takes into account the characteristics of NAND flash memory-based storage devices (such as solid-state disks, eMMC, and SD cards), which are widely used in computer systems ranging from mobile devices to servers. F2FS was designed on a basis of a log-structured file system approach, which is adapted to newer forms of storage. Jaegeuk Kim, the principal F2FS author, has stated that it remedies some known issues of the older log-structured file systems, such as the snowball effect of wandering trees and high cleaning overhead. In addition, since a NAND-based storage device shows different characteristics according to its internal geometry or flash memory management scheme (such as the Flash Translation Layer or FTL), it supports various parameters not only for configuring on-disk layout, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Samsung Electronics
Samsung Electronics Co., Ltd. (, sometimes shortened to SEC and stylized as SΛMSUNG) is a South Korean multinational electronics corporation headquartered in Yeongtong-gu, Suwon, South Korea. It is the pinnacle of the Samsung chaebol, accounting for 70% of the group's revenue in 2012. Samsung Electronics has played a key role in the group's corporate governance due to circular ownership. Samsung Electronics has assembly plants and sales networks in 74 countries and employs around 290,000 people. It is majority-owned by foreign investors. Samsung Electronics is the world's second-largest technology company by revenue, and its market capitalization stood at US$520.65 billion, the 12th largest in the world. Samsung is a major manufacturer of Electronic Components such as lithium-ion batteries, semiconductors, image sensors, camera modules, and displays for clients such as Apple, Sony, HTC, and Nokia. It is the world's largest manufacturer of mobile phones and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snowball Effect
A snowball effect is a process that starts from an initial state of small significance and builds upon itself, becoming larger (graver, more serious), and also perhaps potentially dangerous or disastrous (a vicious circle), though it might be beneficial instead (a virtuous circle). This is a cliché in cartoons and modern theatrics and it is also used in psychology. The common analogy is with the rolling of a snowball down a snow-covered hillside. As it rolls the ball will pick up more snow, gaining more mass and surface area, and picking up even more snow and momentum as it rolls along. In aerospace engineering, it is used to describe the multiplication effect in an original weight saving. A reduction in the weight of the fuselage will require less lift, meaning the wings can be smaller. Hence less thrust is required and therefore smaller engines, resulting in a greater weight saving than the original reduction. This iteration can be repeated several times, although the decreas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arch Linux
Arch Linux () is an independently developed, x86-64 general-purpose Linux distribution that strives to provide the latest stable versions of most software by following a rolling-release model. The default installation is a minimal base system, configured by the user to only add what is purposely required. Pacman, a package manager written specifically for Arch Linux, is used to install, remove and update software packages. Arch Linux uses a rolling release model, meaning there are no "major releases" of completely new versions of the system; a regular system update is all that is needed to obtain the latest Arch software; the installation images released every month by the Arch team are simply up-to-date snapshots of the main system components. Arch Linux has comprehensive documentation, consisting of a community-run wiki known as the ArchWiki. History Inspired by CRUX, another minimalist distribution, Judd Vinet started the Arch Linux project in March 2002. The name was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Huawei P9
The Huawei P9 is a Chinese high-end Android smartphone produced by Huawei, released in 2016. It is the successor to the Huawei P8 and maintains almost the same design but has a dual camera setup in the back co-engineered with Leica along with a fingerprint sensor. The Huawei P9 has a 5.2-inch Full HD IPS-NEO LCD display and runs on Android 6.0 Marshmallow OS. Release The P9 was released in April 2016 in London and in August 2016 in India. New features The P9 added a fingerprint sensor, and was the first Huawei smartphone with a camera co-engineered with Leica under a partnership announced in February 2016. The camera system integrates images from dual rear camera sensors, one monochrome, the other three-colour, which makes possible greater contrast, better low-light images, and shallow depth of field effects, and also refocusing after image capture. Storing two versions of images increases memory use, so there is also a microSD slot to increase storage capacity. Variants The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pixel 3
The Pixel 3 and Pixel 3 XL are a pair of Android smartphones designed, developed, and marketed by Google as part of the Google Pixel product line. They collectively serve as the successors to the Pixel 2 and Pixel 2 XL. They were officially announced on October 9, 2018 at the Made by Google event and released in the United States on October 18. On October 15, 2019, they were succeeded by the Pixel 4 and Pixel 4 XL. Following diminished sales of the Pixel 3 lineup, on May 7, 2019 Google announced midrange variants at I/O 2019, the Pixel 3a and Pixel 3a XL. Specifications Design The Pixel 3 and Pixel 3 XL come in three colors: 'Just Black' (all black), 'Clearly White' (white with a mint green power button), and 'Not Pink' (pink, with an orange power button). The Pixel 3's bezels are significantly smaller than its predecessor's. The Pixel 3 XL is the first Pixel device to use a display notch. They both run on Android Pie natively and both have access to Android 12. The di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nexus 9
The Nexus 9 (codenamed Volantis or Flounder) is a tablet computer co-developed by Google and HTC that runs the Android operating system. It is the fourth tablet in the Google Nexus series, a family of Android consumer devices marketed by Google and built by an OEM partner. The device is available in two storage sizes, 16 GB for US$399 and 32 GB for US$479. Along with the Nexus 6 mobile phone and Nexus Player digital media device, the Nexus 9 launched with 5.0 Lollipop, which offered several new features, notably a modified visual appearance, and the complete replacement of the Dalvik virtual machine with ART. Google has included an additional step to "Enable OEM unlock" before users can unlock the Nexus 9 bootloader. Release The Nexus 9 was announced on 15 October 2014, with pre-orders available on 17 October and was released on 3 November 2014. A 4G LTE version was released in the US on 12 December 2014. Specifications Hardware The Nexus 9 tablet features ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inode
The inode (index node) is a data structure in a Unix-style file system that describes a file-system object such as a file or a directory. Each inode stores the attributes and disk block locations of the object's data. File-system object attributes may include metadata (times of last change, access, modification), as well as owner and permission data. A directory is a list of inodes with their assigned names. The list includes an entry for itself, its parent, and each of its children. Etymology There has been uncertainty on the Linux kernel mailing list about the reason for the "i" in "inode". In 2002, the question was brought to Unix pioneer Dennis Ritchie, who replied: A 1978 paper by Ritchie and Ken Thompson bolsters the notion of "index" being the etymological origin of inodes. They wrote: Additionally, Maurice J. Bach wrote that an inode "is a contraction of the term index node and is commonly used in literature on the UNIX system". Details A file system relies on d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filesystem-level Encryption
Filesystem-level encryption, often called file-based encryption, FBE, or file/folder encryption, is a form of disk encryption where individual files or directories are encrypted by the file system itself. This is in contrast to the full disk encryption where the entire partition or disk, in which the file system resides, is encrypted. Types of filesystem-level encryption include: * the use of a 'stackable' cryptographic filesystem layered on top of the main file system * a single ''general-purpose'' file system with encryption The advantages of filesystem-level encryption include: * flexible file-based key management, so that each file can be and usually is encrypted with a separate encryption key * individual management of encrypted files e.g. incremental backups of the individual changed files even in encrypted form, rather than backup of the entire encrypted volume * access control can be enforced through the use of public-key cryptography, and * the fact that cryptographi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Operations
In concurrent programming, an operation (or set of operations) is linearizable if it consists of an ordered list of invocation and response events ( event), that may be extended by adding response events such that: # The extended list can be re-expressed as a sequential history (is serializable). # That sequential history is a subset of the original unextended list. Informally, this means that the unmodified list of events is linearizable if and only if its invocations were serializable, but some of the responses of the serial schedule have yet to return. In a concurrent system, processes can access a shared object at the same time. Because multiple processes are accessing a single object, there may arise a situation in which while one process is accessing the object, another process changes its contents. Making a system linearizable is one solution to this problem. In a linearizable system, although operations overlap on a shared object, each operation appears to take place ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fsck
The system utility fsck (''file system consistency check'') is a tool for checking the consistency of a file system in Unix and Unix-like operating systems, such as Linux, macOS, and FreeBSD. A similar command, CHKDSK, exists in Microsoft Windows and its predecessor, MS-DOS. Pronunciation There is no agreed pronunciation. It can be pronounced "F-S-C-K", "F-S-check", "fizz-check", "F-sack", "fisk", "fishcake", "fizik", "F-sick", "F-sock", "F-sek", "feshk", the sibilant "fsk", "fix", "farsk" or "fusk". Use Generally, fsck is run either automatically at boot time, or manually by the system administrator. The command works directly on data structures stored on disk, which are internal and specific to the particular file system in use - so an fsck command tailored to the file system is generally required. The exact behaviors of various fsck implementations vary, but they typically follow a common order of internal operations and provide a common command-line interface to the user. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Defragmentation
In the maintenance of file systems, defragmentation is a process that reduces the degree of fragmentation. It does this by physically organizing the contents of the mass storage device used to store files into the smallest number of contiguous regions (fragments, ''extents''). It also attempts to create larger regions of free space using compaction to impede the return of fragmentation. Some defragmentation utilities try to keep smaller files within a single directory together, as they are often accessed in sequence. Defragmentation is advantageous and relevant to file systems on electromechanical disk drives (hard disk drives, floppy disk drives and optical disk media). The movement of the hard drive's read/write heads over different areas of the disk when accessing fragmented files is slower, compared to accessing the entire contents of a non-fragmented file sequentially without moving the read/write heads to seek other fragments. Causes of fragmentation Fragmenta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
