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Bioctl
The bio(4) pseudo-device driver and the bioctl(8) utility implement a generic RAID volume management interface in OpenBSD and NetBSD. The idea behind this software is similar to ifconfig, where a single utility from the operating system can be used to control any RAID controller using a generic interface, instead of having to rely on many proprietary and custom RAID management utilities specific for each given hardware RAID manufacturer. Features include monitoring of the health status of the arrays, controlling identification through blinking the LEDs and managing of sound alarms, and specifying hot spare disks. Additionally, the softraid configuration in OpenBSD is delegated to bioctl as well; whereas the initial creation of volumes and configuration of hardware RAID is left to card BIOS as non-essential after the operating system has already been booted. Interfacing between the kernel and userland is performed through the ioctl system call through the /dev/bio pseudo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NetBSD
NetBSD is a free and open-source Unix-like operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was fork (software development), forked. It continues to be actively developed and is available for many platforms, including servers, desktops, handheld devices, and embedded systems. The NetBSD project focuses on code clarity, careful design, and portability across many computer architectures. Its source code is publicly available and Permissive free software licence, permissively licensed. History NetBSD was originally derived from the 4.3BSD-Reno release of the Berkeley Software Distribution from the Computer Systems Research Group of the University of California, Berkeley, via its Net/2 source code release and the 386BSD project. The NetBSD project began as a result of frustration within the 386BSD developer community with the pace and direction of the operating system's development. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ioctl
In computing, ioctl (an abbreviation of input/output control) is a system call for device-specific input/output operations and other operations which cannot be expressed by regular file semantics. It takes a parameter specifying a request code; the effect of a call depends completely on the request code. Request codes are often device-specific. For instance, a CD-ROM device driver which can instruct a physical device to eject a disc would provide an ioctl request code to do so. Device-independent request codes are sometimes used to give userspace access to kernel functions which are only used by core system software or still under development. The ioctl system call first appeared in Version 7 of Unix under that name. It is supported by most Unix and Unix-like systems, including Linux and macOS, though the available request codes differ from system to system. Microsoft Windows provides a similar function, named "DeviceIoControl", in its Win32 API. Background Conventional op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAID Controller
A disk array controller is a device that manages the physical disk drives Data storage is the recording (storing) of information (data) in a storage medium. Handwriting, phonographic recording, magnetic tape, and optical discs are all examples of storage media. Biological molecules such as RNA and DNA are cons ... and presents them to the computer as logical units. It often implements hardware RAID, thus it is sometimes referred to as RAID controller. It also often provides additional disk cache (computing), cache. ''Disk array controller'' is often ambiguously shortened to ''disk controller'' which can also refer to the circuitry responsible for managing internal disk drive operations. Front-end and back-end side A disk array controller provides front-end interfaces and back-end interfaces. * The back-end interface communicates with the controlled disks. Hence, its protocol is usually Advanced Technology Attachment, ATA (a.k.a. PATA), Serial ATA, SATA, SCSI, Fibre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Envsys
The envsys framework is a kernel-level hardware monitoring sensors framework in NetBSD. , the framework is used by close to 85 device drivers to export various environmental monitoring sensors, as evidenced by references of the sysmon_envsys_register symbol within the sys path of NetBSD; with temperature sensors, ENVSYS_STEMP, being the most likely type to be exported by any given driver. Sensors are registered with the kernel through sysmon_envsys(9) API. Consumption and monitoring of sensors from the userland is performed with the help of envstat utility through proplib(3) through ioctl(2) against the /dev/sysmon pseudo-device file, the powerd power management daemon that responds to kernel events by running scripts from /etc/powerd/scripts/, as well as third-party tools like symon and GKrellM from pkgsrc. Features The framework allows the user to amend the monitoring limits specified by the driver, and for the driver to perform monitoring of the sensors in kernel sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Blob
In the context of free and open-source software, proprietary software only available as a binary executable is referred to as a blob or binary blob. The term usually refers to a device driver module loaded into the kernel of an open-source operating system, and is sometimes also applied to code running outside the kernel, such as system firmware images, microcode updates, or userland programs. The term '' blob'' was first used in database management systems to describe a collection of binary data stored as a single entity. When computer hardware vendors provide complete technical documentation for their products, operating system developers are able to write hardware device drivers to be included in the operating system kernels. However, some vendors, such as Nvidia, do not provide complete documentation for some of their products and instead provide binary-only drivers. This practice is most common for accelerated graphics drivers, wireless networking devices, and ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OpenBSD
OpenBSD is a security-focused operating system, security-focused, free software, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by fork (software development), forking NetBSD 1.0. The OpenBSD project emphasizes software portability, portability, software standard, standardization, software bug, correctness, proactive computer security, security, and integrated cryptography. The OpenBSD project maintains portable versions of many subsystems as package manager, packages for other operating systems. Because of the project's preferred BSD license, which allows binary redistributions without the source code, many components are reused in proprietary and corporate-sponsored software projects. The firewall (computing), firewall code in Apple Inc., Apple's macOS is based on OpenBSD's PF (firewall), PF firewall code, Android (operating system), Android's Bionic (software), Bionic C standard library is based on OpenBSD c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudo-device
In Unix-like operating systems, a device file, device node, or special file is an interface to a device driver that appears in a file system as if it were an ordinary file. There are also special files in DOS, OS/2, and Windows. These special files allow an application program to interact with a device by using its device driver via standard input/output system calls. Using standard system calls simplifies many programming tasks, and leads to consistent user-space I/O mechanisms regardless of device features and functions. Overview Device files usually provide simple interfaces to standard devices (such as printers and serial ports), but can also be used to access specific unique resources on those devices, such as disk partitions. Additionally, device files are useful for accessing system resources that have no connection with any actual device, such as data sinks and random number generators. There are two general kinds of device files in Unix-like operating systems, know ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SCSI Enclosure Services
SCSI Enclosure Services (SES) is a protocol for more modern SCSI enclosure products. An initiator can communicate with the enclosure using a specialized set of SCSI commands to access power, cooling, and other non-data characteristics. SES devices There are two major classes of SES devices: * Attached enclosure services devices allow SES communication through a logical unit within one SCSI disk drive located in the enclosure. The disk-drive then communicates with the enclosure by some other method, the only commonly used one being Enclosure Services Interface (ESI). In fault-tolerant enclosures, more than one disk-drive slot has ESI enabled to allow SES communications to continue even after the failure of any of the disk-drives. The definition of the ESI protocols is owned by an ANSI committee and defined in their specifications ANSI SFF-8067 and SFF-8045. * Standalone enclosure services enclosures have a separate SES processor which occupies its own address on the SCSI bus. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SAF-TE
In computer storage, SAF-TE (abbreviated from SCSI Accessed Fault-Tolerant Enclosure) is an industry standard to interface an enclosure in-band to a (parallel) SCSI subsystem in order to gain access to information or control for various elements and parameters. These include temperature, fan status, slot status (populated/empty), door status, power supplies, alarms, and indicators (e.g. LEDs, LCDs).SAF-TE IR ''1.0 Introduction'' Practically, any given SAF-TE device will only support a subset of all possible sensors or controls.SAF-TE IR ''3.0 SAF-TE Interface'' Scope Many RAID controllers can utilize a SAF-TE "activated" backplane by detecting a swapped drive (after a defect) and automatically starting a rebuild. A passive subsystem usually requires a manual rescan and rebuild. A SAF-TE device (SEP) is represented as a SCSI processor device that is polled every few seconds by e.g. the RAID controller software. Due to the low overhead required, impact on bus performance is neg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAID
RAID (; redundant array of inexpensive disks or redundant array of independent disks) is a data storage virtualization technology that combines multiple physical Computer data storage, data storage components into one or more logical units for the purposes of data redundancy, performance improvement, or both. This is in contrast to the previous concept of highly reliable mainframe disk drives known as ''single large expensive disk'' (''SLED''). Data is distributed across the drives in one of several ways, referred to as RAID levels, depending on the required level of redundancy (engineering), redundancy and performance. The different schemes, or data distribution layouts, are named by the word "RAID" followed by a number, for example RAID 0 or RAID 1. Each scheme, or RAID level, provides a different balance among the key goals: reliability engineering, reliability, availability, computer performance, performance, and computer data storage#Capacity, capacity. RAID levels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Supply Unit (computer)
A power supply unit (PSU) converts Mains electricity, mains AC to low-voltage regulated DC power for the internal components of a desktop computer. Modern personal computers universally use switched-mode power supply, switched-mode power supplies. Some Power supply, power supplies have a manual switch for selecting input voltage, while others automatically adapt to the main voltage. Most modern desktop personal computer power supplies conform to the ATX, ATX specification, which includes form factor and voltage tolerances. While an ATX power supply is connected to the mains supply, it always provides a 5-volt standby (5VSB) power so that the standby functions on the computer and certain peripherals are powered. ATX power supplies are turned on and off by a signal from the motherboard. They also provide a signal to the motherboard to indicate when the DC voltages are in spec, so that the computer is able to safely power up and boot. The most recent ATX PSU standard is version 3.0 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hardware Monitoring
A system monitor is a hardware or software component used to monitor system resources and performance in a computer system. Among the management issues regarding use of system monitoring tools are resource usage and privacy. Monitoring can track both input and output values and events of systems. Overview Software monitors occur more commonly, sometimes as a part of a widget engine. These monitoring systems are often used to keep track of system resources, such as CPU usage and frequency, or the amount of free RAM. They are also used to display items such as free space on one or more hard drives, the temperature of the CPU and other important components, and networking information including the system IP address and current rates of upload and download. Other possible displays may include the date and time, system uptime, computer name, username, hard drive S.M.A.R.T. data, fan speeds, and the voltages being provided by the power supply. Less common are hardware-based s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
