Questions tagged [sar]

System Activity Report: a Unix/Linux command to display various system loads (Wikipedia).

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Comparing perf-tool's bitesize vs sar -d output's avgrq-sz

Here are two outputs from the same time. sar -d -p 10:14:19 AM DEV tps rd_sec/s wr_sec/s avgrq-sz avgqu-sz await svctm %util 10:14:20 AM sdc 0.00 0.00 ...
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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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Stop sysstat sar

How to stop sar collecting system activity without uninstalling sysstat? I have used systemctl stop sysstat but as I understand from running sar it continues collecting system activity.
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70 views

Control-C sends control-alt-delete to my Ubuntu server over ssh

On my Ubuntu VM: Linux xxxxxxx 3.19.0-25-generic #26~14.04.1-Ubuntu SMP Fri Jul 24 21:16:20 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux to which I am connected over SSH, I am running this command: sar ...
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377 views

sar + get network info from sar

this syntax give the network info on sa1 file sar -n DEV -f /var/log/sa/sa1 how to get the info only from UDP protocol ? we try also sar -n UDP -f /var/log/sa/sa1 Requested activities not ...
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sar -dp reports individual disks higher than their devicemapper logical volume

I am trying to figure out how sysstat is reporting the utilization of the device mapper logical volume, lower than the individual disks that make up the logical volume. I keep trying to do the math ...
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203 views

Update sa reports every 6 hours

On SuSE Linux the default cron-job for sa/sar looks like this: # /etc/cron.d/sysstat # Activity reports every 10 minutes everyday */10 * * * * root [ -x /usr/lib64/sa/sa1 ] && exec /usr/lib64/...
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reducing tps in kafka disks on linux

we're using kafka brokers with: 24 HT cores 256GB RAM 16 X 7.2K RPM NLSAS disks configured in RAID-10 and replication factor 3. the sar -q command the runq-sz reached ~40 on average, load average ...
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475 views

After installing sysstat on an AWS EC2 instance: kernel: ena: Feature 27 isn't supported

After installing and enabling sysstat on an AWS EC2 instance I get the following log entries everytime sysstat is run (from the cronjob in /etc/cron.d/sysstat) in my /var/log/syslog file on Debian: ...
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How does sar collect/calculate disk utilization %?

I'm pretty sure sar's disk utilization % shows how much of the disk is being utilized at any given time, but how does it calculate that? I found: %util Percentage of CPU time during which I/O ...
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741 views

How is rxkB/s and wxkB/s calculated in SAR -n DEV command?

sar -n DEV 1 1 command gives the stats rxkB/s(Number of kilobytes read from the device per second.) and wxkB/s (Number of kilobytes written to the device per second.) Is it possible to calculate ...
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12k views

sar: enable data collecting

I've just installed the sysstat package on Manjaro. When running sar for the first time I see: Cannot open /var/log/sa/sa21: No such file or directory Please check if data collecting is enabled How ...
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104 views

Take all sadc (sar) data from production, and analyze it on another machine

sadc is running on the production server. When a incident happens, I want the admin to give me all the data (going back in the past as far as possible) so that I can analyze the incident and also ...
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273 views

How to view historical usage metrics, per process?

My first inclination here would be something built into SAR, or the sysstat package in general. If that is indeed the case however, I can't seem to find this solution. What I would like to see, and ...
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1k views

How to find network latency for network interfaces using SAR on linux environment

I want to get the network latency for network interfaces using SAR on linux environment. sar -n command provides following output: 10:00:13 AM IFACE rxpck/s txpck/s rxkB/s txkB/s rxcmp/s ...
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791 views

What's the caculation for network speed reported with sar-n DEV output?

I am confused about the network speed outputs: If the report says: sar -n DEV 1 1 Linux 2.6.18-194.el5PAE (dev-db) 03/26/2011 _i686_ (8 CPU) 01:11:13 PM IFACE rxpck/s txpck/s ...
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260 views

sar-like Utility For File Access

I'm troubleshooting a linux server's performance degradation from last night. I have sysstat installed on the server and it's polling every 2 minutes. At around the time the event happened, there ...
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347 views

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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367 views

What is the best way to analyze data captured from sar?

I've got some sysstat data that has been captured from servers with SAR, and I'm unsure what is the best way to analyze that data. I've found ksar, but it seems to be quite old and out of date. I'd ...
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168 views

Does an NFS client incur read/write page faults proportional to bytes read to/written from server?

Perhaps my knowledge of virtual memory has been supplanted by too much other junk. Recently I ran some database benchmark tests where all data was to be stored on an NFS server and accessed via NFSv3 ...
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25k views

How to find what processes were running at a time in the past?

I am asked to investigate a high CPU usage alert which occurred this morning. I used sar -p and saw the high CPU usage showing up at that time Next I used ps -eo pcpu,pid,user,args | sort -r -k1 | ...
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215 views

HP UX iostat on File System

I have a server running HP UX 11 OS and I'm trying to have I/O statistics for File System and not disk. For example, I have 50 disk attached to the server when I type iostat (here under output of ...
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761 views

Shell Script to check CPU Utilisation

I am trying to write a shell script which will check free memory of the server. I am trying below code top -M -n1 | grep "Mem" | awk '{print 0 + $7}' | awk '{ print $1 / 1024 }' | awk '{if ($1 < ...
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how to filter sar -d disk output tidily

sar -D output-I would like a suitable command to run alongside stress -hdd but this is the output which sar -D 1 10 gives. I have filtered it using both awk |'NR > 1 {printf "%4s%8s%8s\n",$13,$14,$...
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Why top output different from sar output?

This is SLES11sp3 system. The command top shows the load average of 17+, as shown below: #top top - 11:59:14 up 19 days, 21:55, 40 users, load average: 17.09, 17.29, 19.22 Tasks: 514 total, 1 ...
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1k views

interpreting disk stats using sar

I have JBOD and Cassandra installed on it. I'm trying to figure out if my disk are totally free or they are boring. The sar -d result is in the end. As I understand until %util is low (less then 1) it ...
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What is the difference between sar -B verses sar -W

I am trying to understand why my system is running slowly. I found the sar command, but wanted to know the difference between sar -B and sar -W I read the man page, and I understand that -B gives me ...
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158 views

High load on a particular time

I am facing one odd problem in one of my remote servers (Centos 6). Its load became high by 09:30 AM and became normal by 09:40. See my SAR -q on 2 days. 09:00:01 PM 4 199 0.95 ...
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260 views

Nor able to parse the SAR output

We are using SuSE 10 OS and lately I wish to know the total network bandwidth used for a period of time lets say for 1 week. We have sar enabled and the sar data for a week is there. Now I know how ...
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4k views

How to Change sysstat/sar logging folder

I have just enabled sysstat on one of my servers (Ubuntu 12.04), I have noticed it is logging all to /var/log/sysstat/sa04 /var/log/sysstat/sa05 /var/log/sysstat/sar04 How can I change the sysstat ...
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6k views

opening sar activity files error “Invalid system activity file”

Note: I opened this question on Stackoverflow first and realized that this is the right place for the question. Just stating that it is not a duplicate, already closed the question on SO. I am new ...
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1answer
3k views

report per-process IO stats with pidstat or sar

I'm trying to track io usage of a few "suspect" processes over time. Ideally would like to make those stats available via munin, or push directly to graphite. However, as a starting point it would be ...
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346 views

High CPU usage in RHEL machine

I have RHEL machine that runs postgres-9.1 database. In a particular time, sar output shows as follows: Refer link for snapshot: http://imgur.com/gKcOhOX,vNwTpwC#0 where as %user is high between 12:...
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2k views

Why are pgpgin/s and majflt/s inconsistent in sar -B?

In sar -B ouptut, I would naively expect pgpgin/s to equal majflt/s multiplied by the system page size. From man sar: pgpgin/s Total number of kilobytes the system paged in ...
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3answers
26k views

Relation between disk IOPS and sar tps

I'm trying to estimate IOPS requirements of my application running on 32-bit CentOS 6.2. I started to take some measurement on a machine with SATA disks and I'm quite confused of difference between ...
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2answers
1k views

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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409 views

How to find DEVICE on which read per second (rd_sec/s) is highest?

I am using awk to find out DEVICE on which read per second (rd_sec/s) is highest, (from SAR file) below is my command : # sar -d -f sa28 | awk '{print $3,$4}' |sort -k1,1n Output is showing on ...
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1answer
203 views

How to track down sudden increase in process numbers (linux)

I find it pretty common for a Linux server to slow down to the point of complete unresponsiveness (LA 150+ etc), which when looking at it later using sar or munin or whatever it will show a sudden ...
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3answers
20k views

High await in sar

My database server has the following sar output for the data device: [postgres@dbsrv07 ~]$ LC_ALL=POSIX sar -d |egrep "await|dev253-2" 00:00:01 DEV tps rd_sec/s wr_sec/s avgrq-sz ...
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13k views

Invalid system activity (sysstat) file on Ubuntu server

I'm periodically getting this message from the daily cron on my server. (I don't get this message every day.) /etc/cron.daily/sysstat: Invalid system activity file: /var/log/sysstat//sa28 Here's ...
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1answer
8k views

Sar: Free memory statistics (including buffers, cache)

The free commands gives the amount of free memory in two forms: completely free memory (the Mem line) and disposable memory used for caches and buffers (the -/+ buffers/cache line): -bash-3.2$ free -...
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2answers
5k views

Linux SAR/SAT Daily Reports to store more than a month?

I'm on RHEL. How can i extend the log interval of SAR Reports to be more then a month? Normally the daily SAR reports are something like: [root@server /]# cat /var/log/sa/sa sa01 sa21 sa23 ...
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10k views

CRON opens and closes sessions continuously

I'm seeing a huge amount of these lines in my auth logs: Dec 31 03:45:01 xxxxxxx CRON[17259]: pam_unix(cron:session): session opened for user root by (uid=0) Dec 31 03:45:01 xxxxxxx CRON[17259]: ...
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How to use Sar and kSar

How do I use sar to generate monitoring files on a remote server that I can then copy to my local and graph with the kSar tool? (My server can only be accessed via the cmd)
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2answers
21k views

Shell script to notify when CPU usage goes to 100%

sar -u 1 | awk '{print $9}' so this will give me "CPU Idle" value every second. I'd like to get email in this case the value goes to "0" 10 times in a row? What would be the appropriate way to do ...
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1answer
368 views

Measuring custom statistics with sar

I have a server application which I think is leaking file handles. I want to track the usage of file descriptors over time on my Linux (ubuntu) server. I've figured out that I can track the number ...
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1answer
395 views

High mysql server load, sar output

I have a MySQL Server that should be performing better than it seems to be. We're running ubuntu on a Amazon Cluster Compute (cc1.4xlarge) Linux ip-10-0-1-60 3.2.0-25-virtual #40-Ubuntu SMP Wed May ...
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2answers
6k views

sa2 -A /var/log/sa/sa13: No such file or directory

I have systat version 7.0.2 and the /etc/sysconfig/sysstat has the entry HISTORY=27, this is on a redhat enterprise server 5.6, the cron setup for this is # run system activity accounting tool every ...
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1answer
8k views

Sar: what does totsck stand for

I'm looking for an explanation of the totsck column for the "sar -n SOCK" output 09:44:06 PM totsck tcpsck udpsck rawsck ip-frag tcp-tw 09:44:09 PM 580 18 5 ...
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2answers
4k views

Does a high run queue length average result in poor performance for a web server?

I'm trying to narrow down the list of suspects of web servers that perform moderately well most of the time with occasional bouts of poor performance. I'm analyzing the data collected and summarized ...