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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-device ... [...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 system calls. 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 operat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NetBSD
NetBSD is a free and open-source Unix operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was 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 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 their 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 four founders of the NetBSD project, Chris Demetriou, Theo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAID Controller
A disk array controller is a device that manages the physical disk drives and presents them to the computer as logical units. It almost always implements hardware RAID, thus it is sometimes referred to as RAID controller. It also often provides additional disk cache. ''Disk array controller'' is often improperly shortened to '' disk controller''. The two should not be confused as they provide very different functionality. Front-end and back-end side A disk array controller provides front-end interfaces and back-end interfaces. * Back-end interface communicates with controlled disks. Hence protocol is usually ATA (a.k.a. PATA), SATA, SCSI, FC or SAS. * Front-end interface communicates with a computer's host adapter (HBA, Host Bus Adapter) and uses: ** one of ATA, SATA, SCSI, FC; these are popular protocols used by disks, so by using one of them a controller may transparently emulate a disk for a computer ** somewhat less popular protocol dedicated for a specific solution: FI ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OpenBSD
OpenBSD is a security-focused, free and open-source, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by forking NetBSD 1.0. According to the website, the OpenBSD project emphasizes "portability, standardization, correctness, proactive security and integrated cryptography." The OpenBSD project maintains portable versions of many subsystems as packages for other operating systems. Because of the project's preferred BSD license, many components are reused in proprietary and corporate-sponsored software projects. The firewall code in Apple's macOS is based on OpenBSD's PF firewall code, Android's Bionic C standard library is based on OpenBSD code, LLVM uses OpenBSD's regular expression library, and Windows 10 uses OpenSSH (OpenBSD Secure Shell) with LibreSSL. The word "open" in the name OpenBSD refers to the availability of the operating system source code on the Internet, although the word "open" in the nam ... [...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 space, ... [...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] |
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] |
Pseudo-device
In Unix-like operating systems, a device file 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, known as ''character ... [...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 hardwa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FreeBSD
FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular open-source BSD operating system, accounting for more than three-quarters of all installed and permissively licensed BSD systems. FreeBSD has similarities with Linux, with two major differences in scope and licensing: FreeBSD maintains a complete system, i.e. the project delivers a kernel, device drivers, userland utilities, and documentation, as opposed to Linux only delivering a kernel and drivers, and relying on third-parties for system software; FreeBSD source code is generally released under a permissive BSD license, as opposed to the copyleft GPL used by Linux. The FreeBSD project includes a security team overseeing all software shipped in the base distribution. A wide range of additional third-party applications may be installe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modus Operandi
A ''modus operandi'' (often shortened to M.O.) is someone's habits of working, particularly in the context of business or criminal investigations, but also more generally. It is a Latin phrase, approximately translated as "mode (or manner) of operating". Term The term is often used in police work when discussing crime and addressing the methods employed by criminals. It is also used in criminal profiling, where it can help in finding clues to the offender's psychology. It largely consists of examining the actions used by the individuals to execute the crime, prevent its detection and facilitate escape.Douglas, J. E. and A. W. Burgess, A. G. Burgess, R. K. Ressler. ''Crime classification manual'' (John Wiley & Sons, 2006) , p. 19-21. A suspect's ''modus operandi'' can assist in their identification, apprehension, or repression, and can also be used to determine links between crimes.Berg, B.L. ''Criminal Investigation'' (McGraw Hill, 2008) In business, ''modus operandi'' is used ... [...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. 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 systems monitoring similar information. Customarily these occupy one or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
