Questions tagged [sar]

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

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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 ...
Tom Hale's user avatar
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13 votes
3 answers
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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 ...
pystole's user avatar
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9 votes
1 answer
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What does the fields in sar -B output mean?

The sar manpage says : pgpgin/s - Total number of kilobytes the system paged in from disk per second. pgpgout/s - Total number of kilobytes the system paged out to disk per second. fault/s ...
rags's user avatar
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8 votes
2 answers
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How do I see what's in the run queue on GNU/Linux?

The load on my server is very high, even though there doesn't seem to be much disk activity and the CPU is idle. Using sar, I can see the run queue is getting full, but is there any way to see what's ...
aaronsw's user avatar
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7 votes
3 answers
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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 ...
MountainX's user avatar
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6 votes
1 answer
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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 | ...
juniorbansal's user avatar
6 votes
2 answers
2k views

sar service has stopped collecting data

We had sar working on our Ubuntu server, but did some work on the server and now it's stopped logging to the day's logfile. sar -b 5 5 This indicates that sar is alive, and monitoring data, but ...
strangerpixel's user avatar
5 votes
4 answers
5k views

CentOS - High CPU Usage at a particular time in the night

I have a CentOS-5 server that has very little load. A typical output of "sar" command shows like this: 02:20:01 PM CPU %user %nice %system %iowait %steal %idle 02:30:01 PM ...
WebTenet Solutions's user avatar
4 votes
3 answers
5k 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 ...
Onitlikesonic's user avatar
4 votes
2 answers
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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 ...
user53925's user avatar
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4 votes
2 answers
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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 ...
DmitrySemenov's user avatar
4 votes
0 answers
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 ...
simonp's user avatar
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3 votes
1 answer
9k 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 -...
Adam Matan's user avatar
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3 votes
3 answers
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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 ...
xpapad's user avatar
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3 votes
5 answers
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What do I need to enable to run sar -d?

When I run sar -d I receive the error message: Requested activities not available in file /var/log/sysstat/sa24 The file does exist, and I can run sar with other flags, but can't see these ...
Ryan Olson's user avatar
3 votes
2 answers
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 ...
wfaulk's user avatar
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3 votes
1 answer
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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 ...
user624558's user avatar
2 votes
2 answers
9k 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 ...
moodywoody's user avatar
2 votes
2 answers
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 ...
Domino's user avatar
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2 votes
1 answer
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Tool to show summarized cpu usage per user

I once saw report that contained information, that within given time frame, total number of x cpu minutes, were used, and this was: - afterwards was list of uids (or usernames), and total number of ...
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2 votes
1 answer
300 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 ...
got2be's user avatar
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2 votes
1 answer
4k 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 ...
Yoav Aner's user avatar
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2 votes
2 answers
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sar command to generate only CPU utilization and network statistics in Linux

I want to be able to generate the system activity report every 30 seconds or every minute and store in a file and use it for diagnostic purposes on my VM. So I give an output file for the sar command ...
Vijay Shankar Kalyanaraman's user avatar
1 vote
2 answers
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 ...
夏期劇場's user avatar
1 vote
1 answer
481 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/...
guettli's user avatar
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1 vote
1 answer
498 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 ...
stonecrusher's user avatar
1 vote
1 answer
198 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 ...
Unnikrishnan's user avatar
1 vote
1 answer
352 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 ...
spoovy's user avatar
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1 vote
1 answer
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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 ...
shalom's user avatar
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1 vote
2 answers
4k views

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 ...
Locane's user avatar
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1 vote
2 answers
2k 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 ...
GP92's user avatar
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1 vote
2 answers
1k views

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)
kapad's user avatar
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1 vote
1 answer
412 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 ...
Will Glass's user avatar
1 vote
1 answer
5k views

top command indicates a different cpu usage than sar command

In my CentOS server, when I check the resources with sar command, user cpu usage is around %15 while in top command the sole 'java' process uses like %99 of cpu. sometimes it's even goes further than %...
SJ.Jafari's user avatar
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1 vote
1 answer
1k views

sar high memory commit %

I've noticed that there's a high percentage of memory committed on this server during a specific timeframe. Although, memory usage still looks fine overall from sar output. I don't see 'out of memory' ...
wabbajack001's user avatar
1 vote
1 answer
799 views

How to write pidstat output to a sadc file for analysis later (sar)

How can I write the output of pidstat to a file for analysis later? In sar, you can monitor usage and write-out to a file for later analysis using the -o argument. From the man page: If ...
Michael Altfield's user avatar
1 vote
1 answer
158 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 ...
Jaor's user avatar
  • 11
1 vote
1 answer
162 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 ...
Nicolas Raoul's user avatar
1 vote
2 answers
1k 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 ...
MrDuk's user avatar
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1 vote
0 answers
317 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 ...
Marc C's user avatar
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1 vote
0 answers
805 views

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,$14,$...
Rory's user avatar
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1 vote
0 answers
150 views

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 ...
Mark's user avatar
  • 119
1 vote
1 answer
494 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 ...
eric's user avatar
  • 111
0 votes
2 answers
13k 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]: ...
MultiformeIngegno's user avatar
0 votes
1 answer
46 views

what is the link between SAR memory output and free command?

I now understand a bit more RAM usage in linux OS and I knwo that I can use free -h to have correct knowledge about RAM utilization in my server. but I also have SAR that is working on my server and I ...
iostrym's user avatar
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0 votes
1 answer
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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....
Emerson Prado's user avatar
0 votes
1 answer
363 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 ...
Ken S.'s user avatar
  • 479
0 votes
1 answer
1k views

SAR statistics on CPU usage

i have Ubuntu server with 2 processors. top command show that mysql eats up to 195%. sar shows the following: 08:30:59 AM CPU %user %nice %system %iowait %steal %idle 08:31:00 ...
ravnur's user avatar
  • 101
0 votes
0 answers
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rhel + disk util is very high , what is the impact for long term

we have backup server with rhel version 7.2 server is VM machine , and OS disk is VMDK disk disk used space is around - 50% , and from smartctl we not see problem as we can see from follwing details ...
King David's user avatar
0 votes
1 answer
170 views

High I/O wait and Context Switches - how to debug

Update: sar -W -B -d output added to bottom of post. I have simulated this on boot. I have uwsgi starting 9 instances of a django app, along with gunicorn for websockets, and dramatiq for queue ...
Tim Nelson's user avatar