Questions tagged [vmstat]
CLI tool that reports information about processes, memory, paging, block IO, traps, and cpu activity
41 questions
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vmstat + on RHEL machine high values of swpd
The swpd field indicates how much swap space has been used; this value increases when the systems physical memory is full and the Linux kernel starts to use the swap partition/file. When the systems ...
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High Load Average in Solaris Operating System - Due to high read I/O
In Linux OS, the load average is dependent on multiple factors like CPU utilization, number of uninterruptible sleep processes, and others. On the other hand, Solaris OS load average is dependent on ...
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sar and top show high cpu usage, but vmstat and ps show low cpu usage. Why?
I'm diagnosing a high CPU usage event, and I found a weird difference between numbers from ps/vmstat, which show almost 0%, and sar/top, which show almost 100% (user + system):
sar 1 5
Linux 2.6.9-67....
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3 different methods to count the number of context switches for a specific workload provide 2 different answers
I have a Centos7 system on a Google cloud machine, running a multithreaded database server that executes a particular set of queries in 70 secs (plus or minus 1 sec). I want to know how many context ...
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runqueue length in vmstat and sar
i am looking at the vmstat output to assess certain performance degradation on our systems, specifically for long runqueue. i find frequently it looks like this on a 8 CPU m/c:
Mon Jun 13 12:14:02 ...
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On Linux, what is the size of pages reported by vmstat command and/or /proc/vmstat?
As many have stated on StackExchange and elsewhere, a typical kernel/mmu page size for Linux is 4 KiB. I have verified that this is the case on my OS/architecture (RHEL 6.6, Intel Xeon E5-2690).
Now ...
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Is the run-queue column in vmstat a sum of values or just one measurement?
When I run vmstat on a RHEL 6.6 machine with a time interval I sometimes see the run-queue column jump to "high" values.
I know the first line reported by vmstat is averages since the machine booted ...
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Two identical servers, one of them have 2x CPU load
Http requests are splitted 50/50 between two servers. Servers are running FreeBSD 9.2, their hardware, software & application configurations are absolutely identical. But one of servers is getting ...
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how to efficiently monitor system stat using vmstat?
Am getting the real-time memory stats from vmstat command. I did this using following steps:
$ nohup vmstat 60 > vmstatrecord.app &
the command executes in background and writes the log to ...
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Advice on web server performance troubleshooting is needed
I'm renting a virtual CentOS based server where I have about 5 active sites running. Several months ago I noticed a significant performance degradation in how my sites are running.
First symptom was ...
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Vmstat indicates memory is disappearing
I wanted to profile the memory usage of a script. Here's the output before it was running:
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
r b swpd free buff ...
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Reporting historical system activity in FreeBSD
I'd like to record data about system activity under FreeBSD for future analysis. If I were running a SysV system, I'd just sar and its related utilities, but that doesn't exist in the BSDs. (And ...
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vmstat spend writing/reading explaination
I ran vmstat -D for 1s interval and take the different of milli reading/writing between two interval. Then I start copy a file to test.
bytes write per secs is 23.9M/s, and mili writing is 7244.
As ...
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how can I tell if there is a cpu trashing on my linux machine
I want to write a script that will kill my processes when my machine is doing "too much" swapping of process memory from disk to memory.
What is the best way to determine that? I saw top has %wa and ...
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Huge CS value in #vmstat - what does it mean?
Here is the output for #vmstat for my VPS (Parallels virtualization):
procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
r b swpd free buff cache si so ...
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Top showing 64% idle on first screen or batch run, while there is no idle time at all
I'm running a quite heavy number crunching thing on a few 4 core servers, all running Ubuntu Precise Pangolin LTS 64 bit, in the cloud (so I suppose in a virtualized environment).
To monitor the cpu ...
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What to do if bo value in vmstat is too high?
I don't know what to do about high bo values is vmtstat.
bi is 0 but bo is about 6000. So I don't know what that means and what to do. The application running on server is hanging. I don't know if it ...
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vmstat is consuming most of the CPU power
when I issue the vmstat command without any parameter I get this result:
# vmstat
procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
r b swpd free buff cache ...
- 148
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load average in top and procs in vmstat
As far as I know, the load average in top is the numbers of precess(threads) in running or uninterrupted sleep status, So it should be equal to (procs-r +1 )+ procs-b in vmstat, but in practice, this ...
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vmstat output incompatible
as you can see when run a vmstat like below.
bash-3.00# vmstat 1 5
kthr memory page disk faults cpu
r b w swap free re mf pi po ...
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VMstat explanation needed
can somebody explain me this graph please?
What does it show? What those green peaks mean?
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4k
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awk on vmstat to get si,so
I am writing a shell script to check the vmstat si and so data at various time intervals
vmstat 1 sample output:
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
r b ...
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How do I troubleshoot high vmstat sy
I have a Solaris server with very high vmstat sy time. What tools can I use to identify which process is causing the high system cpu usage?
kthr memory page disk ...
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Getting CPU steal times on Ubuntu 11.4 Virtual Box [closed]
I'm trying to check on CPU steal times in a virtual machine. The goal is for me to be able to detect if my app is running in a VM on over-committed hardware.
I'm currently just testing, in ...
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inonice not working properly in xen dom0
I have a Xen Dom0 (3.2) with a bunch of domUs (paravirt). DomU VBDs are on local LVM volumes. Now I want to get backups of the LVM volumes using snapshots. I use rsync ioniced to idle (ionice -c3).
I ...
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what kind of context switch is counted in the cs parameter in the output of vmstat command
vmstat provides a counter cs for context switch. As this explains, the context switch can be from one process to another , kernel to user or due to a interrupt being fired. Does the cs give a total of ...
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Very long IO wait times
Following scenario has happened twice with different RAID controllers. One was LSI MegaRAID running RAID5, the second was HP Smart Array E200i running RAID1. At first server works smoothly for few ...
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Performance Tuning a High-Load Apache Server
I am looking to understand some server performance problems I am seeing with a (for us) heavily loaded web server. The environment is as follows:
Debian Lenny (all stable packages + patched to ...
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Find out which task is generating a lot of context switches on linux
According to vmstat, my Linux server (2xCore2 Duo 2.5 GHz) is constantly doing around 20k context switches per second.
# vmstat 3
procs -----------memory---------- ---swap-- -----io---- -system-- --...
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The CPU idle is set to 99 while using vmstat, what does this mean?
I am confused with the CPU idle time is set to 99. Does this mean the CPU is idle not doing anything for 99% of the time?
#vmstate
procs -----------memory---------- ---swap-- -----io---- --system-- --...
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running vmstat around a command
Im trying to automate a long list of database experiments. I would like to save vmstat output while specific parts of the experiments are running.
Does something exist along the lines of time(1) or ...
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Server load high, CPU idle. NFS the cause?
I am running into a scenario where I'm seeing a high server load (sometimes upwards of 20 or 30) and a very low CPU usage (98% idle). I'm wondering if these wait states are coming as part of an NFS ...
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How much resources does vmstat really use?
We have a server running Tru64 Unix, which is our main production server for a single application our organisation uses. The software vendor has complete control of the hardware and software (we ...
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determining free memory from command line on Windows
I would like to monitor the free memory on four machines each running Windows Server 2003 R2 SP2 64-bit. Each box has 31.7gb of RAM. I would like to periodically run a command line tool so I can ...
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Interpretation of non-zero vmstat “bi/bo” values
What are useful rule-of-thumbs with regard to interpreting non-zero vmstat "bi/bo" values? When are the values "okay" and when are they an indication of that the system is under heavy stress?
The ...
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Interpretation of non-zero vmstat "si/so" values
What are useful rule-of-thumbs with regard to interpreting non-zero vmstat "si/so" values? When are the values "okay" and when are they an indication of that the memory situation is problematic?
The ...
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Chop headers off of vmstat command?
Is there a way to run the VMSTAT command (or something like it) and have a timestamp be included in the line? I know that I can pipe the output of the command and manipulate the results, but if I do ...
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How would you interpret the following vmstat output?
Consider the following five machines (named c, h, j, s and u) and their respective vmstat 1 outputs.
Given the information from the vmstat output:
Which machines would you consider being in a good ...
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Vmstat seems to give non-standard values?
We have a proprietry system, which runs on Tru64 Unix.
It is a terminal based system.
We are able to use the login 'vmstat' to the system which brings up a vmstat-like view.
However, the information ...
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How to get % memory usage with vmstat?
I need to get a memory usage in % from vmstat, but I don't quite understand some of the numbers relating to memory displayed in vmstat.
In particular, given an output like this
procs -----------...
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vmstat -f shows large number of forks
I have a production server that is showing a very large number of forks when running vmstat -f. Any suggestions on steps that could be used to help find out what the origin of the forks are?
vmstat -...
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