translating by cvsher Linux Performance Monitoring with Vmstat and Iostat Commands ================================================================================ This is our on-going series of commands and performance monitoring in **Linux**. **Vmstat** and **Iostat** both commands are available on all major **Unix-like (Linux/Unix/FreeBSD/Solaris)** Operating Systems. If **vmstat** and **iostat** commands are not available on your box, please install **sysstat** package. The **vmstat**, **sar** and **iostat** commands are the collection of package included in **sysstat** – the system monitoring tools. The iostat generates reports of **CPU** & all device statistics. You may download and install **sysstat** using source tarball from link [sysstat][1], but we recommend installing through **YUM** command. ![Linux Performance Monitoring with Vmstat and Iostat](http://www.tecmint.com/wp-content/uploads/2012/09/Linux-VmStat-Iostat-Commands.png) Linux Performance Monitoring with Vmstat and Iostat ### Install Sysstat in Linux ### # yum -y install sysstat - **vmstat** – Summary information of Memory, Processes, Paging etc. - **iostat** – Central Processing Unit (CPU) statistics and input/output statistics for devices and partitions. ### 6 Vmstat Command Examples in Linux ### #### 1. List Active and Inactive Memory #### In the below example, there are six columns. The significant of the columns are explained in man page of **vmstat** in details. Most important fields are **free** under memory and **si**, **so** under swap column. [root@tecmint ~]# vmstat -a procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu----- r b swpd free inact active si so bi bo in cs us sy id wa st 1 0 0 810420 97380 70628 0 0 115 4 89 79 1 6 90 3 0 - **Free** – Amount of free/idle memory spaces. - **si** – Swaped in every second from disk in Kilo Bytes. - **so** – Swaped out every second to disk in Kilo Bytes. **Note**: If you run **vmstat** without parameters it’ll displays summary report since system boot. #### 2. Execute vmstat ‘X’ seconds and (‘N’number of times) #### With this command, **vmstat** execute every two seconds and stop automatically after executing six intervals. [root@tecmint ~]# vmstat 2 6 procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 0 0 0 810420 22064 101368 0 0 56 3 50 57 0 3 95 2 0 0 0 0 810412 22064 101368 0 0 0 0 16 35 0 0 100 0 0 0 0 0 810412 22064 101368 0 0 0 0 14 35 0 0 100 0 0 0 0 0 810412 22064 101368 0 0 0 0 17 38 0 0 100 0 0 0 0 0 810412 22064 101368 0 0 0 0 17 35 0 0 100 0 0 0 0 0 810412 22064 101368 0 0 0 0 18 36 0 1 100 0 0 #### 3. Vmstat with timestamps #### **vmstat** command with **-t** parameter shows timestamps with every line printed as shown below. [tecmint@tecmint ~]$ vmstat -t 1 5 procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------ ---timestamp--- r b swpd free buff cache si so bi bo in cs us sy id wa st 0 0 0 632028 24992 192244 0 0 70 5 55 78 1 3 95 1 0 2012-09-02 14:57:18 IST 1 0 0 632028 24992 192244 0 0 0 0 171 514 1 5 94 0 0 2012-09-02 14:57:19 IST 1 0 0 631904 24992 192244 0 0 0 0 195 600 0 5 95 0 0 2012-09-02 14:57:20 IST 0 0 0 631780 24992 192244 0 0 0 0 156 524 0 5 95 0 0 2012-09-02 14:57:21 IST 1 0 0 631656 24992 192244 0 0 0 0 189 592 0 5 95 0 0 2012-09-02 14:57:22 IST #### 4. Statistics of Various Counter #### **vmstat** command and -s switch displays summary of various event counters and memory statistics. [tecmint@tecmint ~]$ vmstat -s 1030800 total memory 524656 used memory 277784 active memory 185920 inactive memory 506144 free memory 26864 buffer memory 310104 swap cache 2064376 total swap 0 used swap 2064376 free swap 4539 non-nice user cpu ticks 0 nice user cpu ticks 11569 system cpu ticks 329608 idle cpu ticks 5012 IO-wait cpu ticks 79 IRQ cpu ticks 74 softirq cpu ticks 0 stolen cpu ticks 336038 pages paged in 67945 pages paged out 0 pages swapped in 0 pages swapped out 258526 interrupts 392439 CPU context switches 1346574857 boot time 2309 forks #### 5. Disks Statistics #### **vmstat** with **-d** option display all disks statistics. [tecmint@tecmint ~]$ vmstat -d disk- ------------reads------------ ------------writes----------- -----IO------ total merged sectors ms total merged sectors ms cur sec ram0 0 0 0 0 0 0 0 0 0 0 ram1 0 0 0 0 0 0 0 0 0 0 ram2 0 0 0 0 0 0 0 0 0 0 ram3 0 0 0 0 0 0 0 0 0 0 ram4 0 0 0 0 0 0 0 0 0 0 ram5 0 0 0 0 0 0 0 0 0 0 ram6 0 0 0 0 0 0 0 0 0 0 ram7 0 0 0 0 0 0 0 0 0 0 ram8 0 0 0 0 0 0 0 0 0 0 ram9 0 0 0 0 0 0 0 0 0 0 ram10 0 0 0 0 0 0 0 0 0 0 ram11 0 0 0 0 0 0 0 0 0 0 ram12 0 0 0 0 0 0 0 0 0 0 ram13 0 0 0 0 0 0 0 0 0 0 ram14 0 0 0 0 0 0 0 0 0 0 ram15 0 0 0 0 0 0 0 0 0 0 loop0 0 0 0 0 0 0 0 0 0 0 loop1 0 0 0 0 0 0 0 0 0 0 loop2 0 0 0 0 0 0 0 0 0 0 loop3 0 0 0 0 0 0 0 0 0 0 loop4 0 0 0 0 0 0 0 0 0 0 loop5 0 0 0 0 0 0 0 0 0 0 loop6 0 0 0 0 0 0 0 0 0 0 loop7 0 0 0 0 0 0 0 0 0 0 sr0 0 0 0 0 0 0 0 0 0 0 sda 7712 5145 668732 409619 3282 28884 257402 644566 0 126 dm-0 11578 0 659242 1113017 32163 0 257384 8460026 0 126 dm-1 324 0 2592 3845 0 0 0 0 0 2 #### 6. Display Statistics in Megabytes #### The **vmstat** displays in **Megabytes** with parameters **-S** and **M**(Uppercase & megabytes). By default **vmstat** displays statistics in kilobytes. [root@tecmint ~]# vmstat -S M 1 5 procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 0 0 0 346 53 476 0 0 95 8 42 55 0 2 96 2 0 0 0 0 346 53 476 0 0 0 0 12 15 0 0 100 0 0 0 0 0 346 53 476 0 0 0 0 32 62 0 0 100 0 0 0 0 0 346 53 476 0 0 0 0 15 13 0 0 100 0 0 0 0 0 346 53 476 0 0 0 0 34 61 0 1 99 0 0 ### 6 Iostat Command Examples in Linux ### #### 7. Display CPU and I/O statistics #### **iostat** without arguments displays **CPU** and **I/O** statistics of all partitions as shown below. [root@tecmint ~]# iostat Linux 2.6.32-279.el6.i686 (tecmint.com) 09/03/2012 _i686_ (1 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 0.12 0.01 1.54 2.08 0.00 96.24 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn sda 3.59 161.02 13.48 1086002 90882 dm-0 5.76 159.71 13.47 1077154 90864 dm-1 0.05 0.38 0.00 2576 0 #### 8. Shows only CPU Statistics #### **iostat** with **-c** arguments displays only **CPU** statistics as shown below. [root@tecmint ~]# iostat -c Linux 2.6.32-279.el6.i686 (tecmint.com) 09/03/2012 _i686_ (1 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 0.12 0.01 1.47 1.98 0.00 96.42 #### 9. Shows only Disks I/O Statistics #### **iostat** with **-d** arguments displays only disks **I/O** statistics of all partitions as shown. [root@tecmint ~]# iostat -d Linux 2.6.32-279.el6.i686 (tecmint.com) 09/03/2012 _i686_ (1 CPU) Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn sda 3.35 149.81 12.66 1086002 91746 dm-0 5.37 148.59 12.65 1077154 91728 dm-1 0.04 0.36 0.00 2576 0 #### 10. Shows I/O statistics only of a single device. #### By default it displays statistics of all partitions, with **-p** and device name arguments displays only disks **I/O** statistics for specific device only as shown. [root@tecmint ~]# iostat -p sda Linux 2.6.32-279.el6.i686 (tecmint.com) 09/03/2012 _i686_ (1 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 0.11 0.01 1.44 1.92 0.00 96.52 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn sda 3.32 148.52 12.55 1086002 91770 sda1 0.07 0.56 0.00 4120 18 sda2 3.22 147.79 12.55 1080650 91752 #### 11. Display LVM Statistics #### With **-N** (Uppercase) parameter displays only **LVM** statistics as shown. [root@tecmint ~]# iostat -N Linux 2.6.32-279.el6.i686 (tecmint.com) 09/03/2012 _i686_ (1 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 0.11 0.01 1.39 1.85 0.00 96.64 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn sda 3.20 142.84 12.16 1086002 92466 vg_tecmint-lv_root 5.13 141.68 12.16 1077154 92448 vg_tecmint-lv_swap 0.04 0.34 0.00 2576 0 #### 12. iostat version. #### With **-V** (Uppercase) parameter displays version of **iostat** as shown. [root@tecmint ~]# iostat -V sysstat version 9.0.4 (C) Sebastien Godard (sysstat orange.fr) **Note**: **vmstat** and **iostat** contains number of columns and flags which may not possible to explain in details. If you want to know more about it you may refer man page of **vmstat** and **iostat**. Please share it if you find this article is useful through our comment box below. -------------------------------------------------------------------------------- via: http://www.tecmint.com/linux-performance-monitoring-with-vmstat-and-iostat-commands/ 作者：[Ravi Saive][a] 译者：[译者ID](https://github.com/译者ID) 校对：[校对者ID](https://github.com/校对者ID) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出 [a]:http://www.tecmint.com/author/admin/ [1]:http://sebastien.godard.pagesperso-orange.fr/download.html