iostat

This article discusses the serious problem of iowait caused by intensive transactions. 1. overview in linux, a database server with dual-sata disks and RAID 1 is installed. I ran a stored procedure and inserted tens of millions of records into a table. This is an intensive small transaction operation. In iostat detection, a large number of I... discuss the serious problem of iowait caused by intensive transactions 1. overview in linux, a database serv

: 0%Cache Size: Not EnteredDuration for each Data Point: 60 secondsSmall Columns:, 0Large Columns:, 0, 1, 2, 3, 4Total Data Points: 15 Name:/dev/mapper/mpath7p1 Size: 536869863424Name:/dev/mapper/mpath8p1 Size: 5368698634242 FILEs found. Maximum Large MBPS = 183.53 @ Small = 0 and Large = 4Maximum Small IOPS = 851 @ Small = 10 and Large = 0Minimum Small Latency = 11.38 @ Small = 3 and Large = 0 4. Comparison and Analysis of resultsDuring stress testing, you can use the

disk I/O Lotop is similar to the top command and the htop program, but it has the statistical function to monitor and display disk I/O in real time. This tool is very useful for precise processes and for discovering high-usage read/write processes. Loptop installation instructions: Install loptop in Linux 8. iostat -- input/output statistics Iostat is a simple tool used to collect and display st

1 Overview 1.1 factors affecting Linux Service Program Performance CPU, memory, disk I/O bandwidth, network I/O bandwidth1.2 Performance Evaluation CPU: user % + sys % Memory: Swap In (si) = 0; Swap Out (so) = 0; the Swap partition is not used. If Swap partition is frequently used, the memory may not be enough. Hard Disk: iowait % Network: as long as you have enough bandwidth to use it, achieving the NIC bandwidth in linux means no pressure. Here: % user: indicates the percentage of time when

Sometimes when we execute a command, we prompt:[Root @ localhost ~] # Iptraf-Bash: iptraf: command not found I believe many of my friends will often encounter this problem.To solve this problem, you need to install the corresponding software package. In many cases, the command name is not necessarily the software package name,The iptraf command here happens to be the name of the software package, which is a better solution. It is OK to directly install the software package. As follows:Yum instal

Iostat for output CPU and disk I/O-related statisticsIostat SyntaxUsage: iostat [options] [Options:[-c] [-d] [-h] [-k |-m] [-X] [-y] [--j {ID | LABEL | PATH | UUID | -T]-G ,...] | Common Options explained:-C: Output avg-CPU results separately, excluding device results -D: Output device results Separately, excluding CPU results -k/-m: Output results in kb/MB instead ofsector number -x: Output More detailed

10.6 Monitoring IO Performance10.7 Free Command10.8 PS Command10.9 Viewing network status10.10 Linux under Grab BagFirst, Iostat and Iotop commandIostat command and Iotop, command to see the system disk work, timely discovery of disk problems, these two tools are not the system comes with, the need for Yum installationWhere the Iostat command is in the same (SYSSTAT) package as the SAR command mentioned in

IO operation for any reason idle time idle time (%) (idle/total) *100Iv. Iostat[Email protected] ~]# iostat--help usage: iostat [options] [Commonly used methods are:[[emailprotected]~]#iostat-d-k2linux2.6.32-279.el6.x86_64 ( node2.buranle.com) 2015 July 29 _x86_64_ (1NBSP;CPU) device: tpskb_read/skb _wrtn/skb_readkb_w

iostat SAR chkconfigsystem security-related commands (10)chmod chown chgrp chage passwd su sudo umask chattr lsattrcommands to view system user login information (7)WhoAmI who w last lastlog users fingerView hardware information related commands (8)ifconfig free fdisk ethtool mii-tool dmidecode dmesg lspciOther (19)echo printf rpm Yum Watch alias Unalias date Clear History Eject time nohup NC xargs exec export unset typeSystem performance Monitoring

system monitoring, diagnostic tools Top There are several types of common combinations:o detection of CPU bottlenecks with Vmstat, SAR, Iostato detect memory bottlenecks with free and vmstato detection of disk I/O bottlenecks with Iostat and DMESGo detection of network bandwidth bottlenecks with Netstat 2.1 Vmstat the meaning of the Vmstat command is to display the virtual memory status ("Viryual memor Statics"), but it can report on the overall op

were done on a memory 64g,sas hard drive.During the test, we need to pay attention to two points, disk read and write speed and IO usage, we use the Iopp and Iostat tools to observe respectively.Test Write Speed:Test write 20G data, the larger the amount of data, the test value should be more accurate.# sync;/usr/bin/time-p Bash-c "(dd If=/dev/zero of=test.dd bs=1m count=20000)"20000+0 Records in20000+0 Records outReal 92.87User 0.00SYS 18.08The time

executing thread, resulting in a large number of context switches. Query basic steps: +-top or Vmstat find the thread and its ID that consume CPU severity and convert this thread ID to a value of 16 +-kill-3 pid or Jstack [-l] PID | [grep ' nid=ox6849 '] to dump the application's Java thread information 2. File IO consumption analysis When using Iostat to view IO consumption, the first thing to focus on is the CPU iowait%, when iowait occupies

When a Linux system encounters a problem, we not only need to view the system log information, but also need to use a large number of performance monitoring tools to determine which part (memory, CPU, hard disk ......) An error occurred. In Linux, all running parameters are stored in the virtual directory/proc. In other words, the data value obtained by the performance monitoring tool is actually derived from this directory, when system overestimates are involved, we can modify the relevant para

space4.2% Sy CPU usage in kernel space0.0% percentage of CPU used by processes that have changed their priorities in Ni user process space76.8% ID idle CPU percentage12% wa CPU time percentage waiting for Input and OutputThe percentage of 12% wa can roughly reflect that the current disk IO requests waiting for input and output are too frequent. For further analysis, we track key process locating programs# Strace-P 28644 (high CPU usage) It indicates that in the multi-thread condition, if concu

statistics. This tool is useful when searching for specific processes and using a large number of disk read/write processes. # Iotop For more information about how to install and use iotop, see install Iotop in Linux. 8. Iostat-input/output statistics Iostat is a simple tool for collecting and displaying input and output status statistics of system storage devices. This tool is often used to track the

Linux System Performance Analysis commands or tools Common commands: Dstat, vmstat, sar, iostat, netstat, free, ps, top, etc.Performance analysis and diagnosis tools Use vmstat, sar, and iostat to detect CPU, disk, and memory bottlenecks. Use free and vmstat to detect memory and IO bottlenecks Use iostat to check whether it is a disk I/O bottleneck Use

Using pidstat to view the usage of process resources introduction many tools provide you with methods to view the usage of system resources from the device perspective. For example, use iostat to View disk io statistics: linux :~ # Iostat-d3Device: tpsBlk_read... use pidstat to view process resource usage introduction many tools provide us with a way to view system resource usage from a device perspective.

as the page cache. generally, it is used as the cache of the file system. if the cache is large, it indicates that there are many files in the cache. if the bi in IO is small at this time, it indicates that the file system is more efficient. The number of swapsi switches from memory to memory swap zone. So the number of memory entries in the memory swap zone. The total amount of data IObi reads from block devices (read disk) (kb per second ). Total data written to bo block devices (disk write)

Why % specified Earlier this month I wrote aboutvmstat iowait cpu numbersand some of the comments I got were advertising the use of util % as reported by the iostat tool instead. I find this number even more useless for MySQL performance tuning and capacity planning. Now let me start by saying this is a really tricky and deceptive number. mongodbas who report instances of their systems having a very busy IO subsystem said the util % in vmstat was abv

)Uptime Top free Vmstat mpstat iostat SAR chkconfigSystem security-related commands (10)chmod chown chgrp chage passwd su sudo umask chattr lsattrCommands to view system user login information (7)WhoAmI who w last lastlog users fingerView hardware information related commands (8)Ifconfig free fdisk ethtool mii-tool dmidecode dmesg LspciOther (19)echo printf rpm Yum Watch alias Unalias date Clear History Eject time nohup NC xargs exec export unset type