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Iostat
iostat (''input/output statistics'') is a computer system monitor tool used to collect and show operating system storage input and output statistics. It is often used to identify performance issues with storage devices, including local disks, or remote disks accessed over network file systems such as NFS. It can also be used to provide information about terminal (TTY) input and output, and also includes some basic CPU information. Syntax and availability iostat -x displays output where each line (row) gives numerical data for one device. The first column lists the device name, and subsequent columns show various statistics for that device. Columns include the average service time (''svc_t'', which includes not only the time a request is in the service queue, but also the seek time and transfer time), the average busy percentage (''%b'', essentially the proportion of time that the device is in use), and the percentage of time that the queue is not empty (''%w'', which means the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iostat Solaris 10
iostat (''input/output statistics'') is a computer system monitor tool used to collect and show operating system storage input and output statistics. It is often used to identify performance issues with storage devices, including local disks, or remote disks accessed over network file systems such as NFS. It can also be used to provide information about terminal (TTY) input and output, and also includes some basic CPU information. Syntax and availability iostat -x displays output where each line (row) gives numerical data for one device. The first column lists the device name, and subsequent columns show various statistics for that device. Columns include the average service time (''svc_t'', which includes not only the time a request is in the service queue, but also the seek time and transfer time), the average busy percentage (''%b'', essentially the proportion of time that the device is in use), and the percentage of time that the queue is not empty (''%w'', which means the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sar (Unix)
System Activity Report (sar) is a Unix System V-derived system monitor command used to report on various system loads, including CPU activity, memory/paging, interrupts, device load, network and swap space utilization. Sar uses /proc filesystem for gathering information. Platform support Sar was originally developed for Solaris operating system and it is available in Linux, Solaris, AIX, HP-UX, but it is not available for macOS or FreeBSD. Prior to 2013 there was a bsdsar tool, but it is now deprecated. Linux distributions, such as Debian, Red Hat Enterprise Linux, SuSe and Ubuntu provide sar utility through the sysstat package. Syntax sar flags -e time -f filename i sec -s time ; : filename Uses filename as the data source for sar. The default is the current daily data file /var/adm/sa/sadd. ; : time Selects data up to time. The default is 18:00. ; : sec Selects data at intervals as close as possible to sec seconds. Example ser@localhost sar # Displays curre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sysstat
sysstat (''system statistics'') is a collection of performance monitoring tools for Linux. It is available on Unix and Unix-like operating systems. Software included in sysstat package: * sar Collect, report, or save system activity information. * iostat (1) reports basic CPU statistics and input/output statistics for devices, partitions and network filesystems. * mpstat(1) reports individual or combined processor related statistics. * pidstat(1) reports statistics for Linux tasks (processes) : I/O, CPU, memory, etc. * nfsiostat(1) reports input/output statistics for network filesystems (NFS). * cifsiostat(1) reports I/O statistics for CIFS resources. References 2. "http://sebastien.godard.pagesperso-orange.fr/". , SYSSTAT Utilities Homepage. Retrieved 21 September 2020 See also * sar (Unix) System Activity Report (sar) is a Unix System V-derived system monitor command used to report on various system loads, including CPU activity, memory/paging, interrupts, de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systat (tool)
systat is a BSD UNIX console application for displaying system statistics in fullscreen mode using ncurses/curses. It is available on, and by default ships in the base systems of, FreeBSD, NetBSD, OpenBSD and DragonFly BSD. It was first released as part of 4.3BSD in . Both internally and in the interface of the user the utility consists of several distinct modules and tabs, referred to as "displays" in FreeBSD, NetBSD and DragonFly, and "views" in OpenBSD, which are automatically refreshed every specified number of seconds. These modules cover all system components, including statistics resembling vmstat, iostat and netstat in all of the BSDs, as well as pf and sensors views in some of the BSDs. The systat utility is notably absent from OS X, where a GUI-based Activity Monitor performs similar functions. See also * vmstat * iostat * top * netstat In computing, netstat (''network statistics'') is a command-line network utility that displays network connections for Tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Monitor
A system monitor is a Computer hardware, 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 Central processing unit, CPU usage and frequency, or the amount of free Random access memory, 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, Uptime, system uptime, computer name, username, hard drive Self-Monitoring, Analysis, and Reporting Technology, S.M.A.R.T. data, Computer fan, fan speeds, and the voltages being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mpstat
mpstat is a computer command-line software used in Unix-type operating systems to report (on the screen) processor-related statistics. It is used in computer monitoring in order to diagnose problems or to build statistics about a computer's CPU usage. Description The mpstat command writes to standard output activities for each available processor. The mpstat command can be used both on SMP and UP machines, but in the latter, only global average activities will be printed. Usage $ mpstat Interval is the time in seconds between printing out a line of statistics. Count is the number of lines of output you want. Note that the first line of output from mpstat (like iostat, vmstat, etc.) contains averages since system boot. The subsequent lines will show current values. Examples Different examples of output under different operating systems: under Linux kernel 4.14 on a two CPU machine: Linux 4.14.24.mptcp (hostname) 05/23/2018 _x86_64_ (2 CPU) 03:51:19 PM CPU ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix-like
A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-like application is one that behaves like the corresponding Unix command or shell. Although there are general philosophies for Unix design, there is no technical standard defining the term, and opinions can differ about the degree to which a particular operating system or application is Unix-like. Some well-known examples of Unix-like operating systems include Linux and BSD. These systems are often used on servers, as well as on personal computers and other devices. Many popular applications, such as the Apache web server and the Bash shell, are also designed to be used on Unix-like systems. One of the key features of Unix-like systems is their ability to support multiple users and processes simultaneously. This allows users to run multipl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix
Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others. Initially intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Berkeley (Berkeley Software Distribution, BSD), Microsoft (Xenix), Sun Microsystems (SunOS/Solaris (operating system), Solaris), Hewlett-Packard, HP/Hewlett Packard Enterprise, HPE (HP-UX), and IBM (IBM AIX, AIX). In the early 1990s, AT&T sold its rights in Unix to Novell, which then sold the UNIX trademark to The Open Group, an industry consortium founded in 1996. The Open Group allows the use of the mark for certified operating systems that comply with the Single UNIX Specification (SUS). Unix systems are chara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AT&T Bell Laboratories
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by multinational company Nokia. With headquarters located in Murray Hill, New Jersey, the company operates several laboratories in the United States and around the world. Researchers working at Bell Laboratories are credited with the development of radio astronomy, the transistor, the laser, the photovoltaic cell, the charge-coupled device (CCD), information theory, the Unix operating system, and the programming languages B, C, C++, S, SNOBOL, AWK, AMPL, and others. Nine Nobel Prizes have been awarded for work completed at Bell Laboratories. Bell Labs had its origin in the complex corporate organization of the Bell System telephone conglomerate. In the late 19th century, the laboratory began as the Western Electric Engineering Department, l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Netstat
In computing, netstat (''network statistics'') is a command-line network utility that displays network connections for Transmission Control Protocol (both incoming and outgoing), routing tables, and a number of network interface (network interface controller or software-defined network interface) and network protocol statistics. It is available on Unix, Plan 9, Inferno, and Unix-like operating systems including macOS, Linux, Solaris and BSD. It is also available on IBM OS/2 and on Microsoft Windows NT-based operating systems including Windows XP, Windows Vista, Windows 7, Windows 8 and Windows 10. It is used for finding problems in the network and to determine the amount of traffic on the network as a performance measurement. On Linux this program is mostly obsolete, although still included in many distributions. On Linux, netstat (part of "net-tools") is superseded by ss (part of iproute2). The replacement for netstat -r is ip route, the replacement for netstat -i is ip -s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disk-drive Performance Characteristics
Higher performance in hard disk drives comes from devices which have better performance characteristics. These performance characteristics can be grouped into two categories: access time and data transfer time (or rate). Access time The ''access time'' or ''response time'' of a rotating drive is a measure of the time it takes before the drive can actually transfer data. The factors that control this time on a rotating drive are mostly related to the mechanical nature of the rotating disks and moving heads. It is composed of a few independently measurable elements that are added together to get a single value when evaluating the performance of a storage device. The access time can vary significantly, so it is typically provided by manufacturers or measured in benchmarks as an average. The key components that are typically added together to obtain the access time are: * Seek time * Rotational latency * Command processing time * Settle time Seek time With rotating drives, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Device Mapper
The device mapper is a framework provided by the Linux kernel for mapping physical block devices onto higher-level ''virtual block devices''. It forms the foundation of the logical volume manager (LVM), software RAIDs and dm-crypt disk encryption, and offers additional features such as file system snapshots. Device mapper works by passing data from a virtual block device, which is provided by the device mapper itself, to another block device. Data can be also modified in transition, which is performed, for example, in the case of device mapper providing disk encryption or simulation of unreliable hardware behavior. This article focuses on the device mapper implementation in the Linux kernel, but the device mapper functionality is also available in both NetBSD and DragonFly BSD. Usage Applications (like LVM2 and Enterprise Volume Management System (EVMS)) that need to create new mapped devices talk to the device mapper via the libdevmapper.so shared library, which in turn issu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
