This article describes how to use “sar” command to analyse system performance in Unix and Linux especially Oracle Solaris.We’ll describe sar command and parameters with examples. By default sar package comes from Oracle Solaris and HP-UX installation but for linux you have to install sysstat package.
Which performance statistics you can monitor with sar command ?
- CPU usage and statistics
- Memory usage and statistics
- Swap usage and statistics
- I/O activities for the system
- Context switch statistics
- Run queue and load avarage
- Network statistics
- Report all data for a spesific time
According to sysstat package describtion it includes following system analyze packages;
| sar | pidstat |
| iostat | sadf |
| mpstat |
You can monitor system performance in real time and also for the past.Let’s check how to install systat package for all type of linux server:
SAR Installation
Ubuntu:
sudo apt-get install sysstat
Centos/Fedora/Red Hat:
yum install sysstat
or
rpm -ivh sysstat-10.xx.rpm
And also you can get sysstat binary file from this SITE and install them on your server. You can download sysstat binary file to your local and put it them to the server with SFTP .Filezilla can be use for file transfer from your local to server.
After you put sysstat bz file under a directory then you can apply these commands .Also read install file to check if you need more.But I recommend you to put “enable-install-cron” option while configure .This option ‘ll create startup file and also cron file for you.(/etc/rc.d/init.d/sysstat)
#tar xvfj sysstat-11.1.8.tar.bz2
cd sysstat-11.1.8
./configure --enable-install-cron
#make
#make install
Enable data collection on SAR
Take a look this Link.You ‘ll get a script to run on your servers.The script which added checks and performs all changes for you. Please first run script on your test server then check if everything is fine then perform same operation for other servers.
After you enabled sar data collection it ‘ll collect all performance data. These files will be located under the directory which I added below.
Oracle Solaris:/var/adm/sa
HP-UX:/var/adm/sa
Linux:/var/log/sa
Command Usage for a spesific time:”-s” start time “-e” end time
#sar -A -f /var/log/sa/sar13 -s 16:00:00 -e 17:00:00
Oracle Solaris:
- Service:
-
svcadm enable system/sar:default
-
- Crontab:
-
## crontab -e sys 0 * * * 0-6 /usr/lib/sa/sa1 20,40 8-17 * * 1-5 /usr/lib/sa/sa1 5 18 * * 1-5 /usr/lib/sa/sa2 -s 8:00 -e 18:01 -i 1200 -A
-
Linux:
- Install sysstat package
- Service:
#cat /etc/sysconfig/sysstat # How long to keep log files (days), maximum is a month HISTORY=7
- Crontab:
[root@testserver ~]# cat /etc/cron.d/sysstat # run system activity accounting tool every 10 minutes */10 * * * * root /usr/lib64/sa/sa1 1 1 # generate a daily summary of process accounting at 23:53 53 23 * * * root /usr/lib64/sa/sa2 -A
HP-UX:
- Be sure /var/adm/sa directory exist
- Crontab:
echo "0 * * * 0,6 /usr/lbin/sa/sa1" >> /usr/spool/cron/crontabs/root echo "0 8-17 * * 1-5 /usr/lbin/sa/sa1 300 3" >> /usr/spool/cron/crontabs/root echo "0 18-7 * * 1-5 /usr/lbin/sa/sa1" >> /usr/spool/cron/crontabs/root
Use SAR Command
Oracle Solaris
Memory Usage Controls:
- How to check page-out and memory with sar for oracle solaris?
- There are two important parameters that you need to check if system needs more memory.
Observed high values at the same time for the pgscan/s and pgfree/s, indicates a memory shortage. Please run “ps -elf|grep -v grep |egrep ‘PID|page'” and check number of cycle for page deamon. - “sar -g” also shows information about inodes recycle state. Check if inodes being recycled too quickly.Recycled inodes can be cause of loss of reusable pages.
- There are two important parameters that you need to check if system needs more memory.
casesup@solaris:~$ sar -g 1 3
SunOS solaris 5.11 11.2 i86pc 10/31/2015
11:29:00 pgout/s ppgout/s pgfree/s pgscan/s %ufs_ipf
11:29:01 0.00 0.00 0.00 0.00 0.00
11:29:02 0.00 0.00 0.00 0.00 0.00
11:29:03 0.00 0.00 0.00 0.00 0.00
Average 0.00 0.00 0.00 0.00 0.00
- How to check Kernel memory usage with sar for oracle solaris?
casesup@solaris:~$ sar -k 1 20 SunOS solaris 5.11 11.2 i86pc 10/31/2015 11:45:19 sml_mem alloc fail lg_mem alloc fail ovsz_alloc fail 11:45:20 332820736 202341008 16070 3998171136 3228714496 0 100196352 0 11:45:21 332820736 202341264 16070 3998171136 3228714496 0 100196352 0 11:45:22 332820736 202341200 16070 3998171136 3228714496 0 100196352 0 11:45:23 332820736 202341088 16070 3998171136 3228714496 0 100196352 0 11:45:24 332820736 202341152 16070 3998171136 3228714496 0 100196352 0 11:45:25 332820736 202341120 16070 3998171136 3228714496 0 100196352 0
- How to check Page-In activity with sar for oracle solaris?
casesup@solaris:~$ sar -p 1 100 SunOS solaris 5.11 11.2 i86pc 10/31/2015 11:49:26 atch/s pgin/s ppgin/s pflt/s vflt/s slock/s 11:49:27 20.59 0.00 0.00 56.86 189.22 0.00 11:49:28 42.42 0.00 0.00 52.53 179.80 0.00 11:49:29 42.00 0.00 0.00 52.00 176.00 0.00
- How to Check Queue Activity with sar for Oracle Solaris?
- runq-sz:The number of process waiting for free Cpu .This value must be less then 2.
casesup@solaris:~$ sar -q 1 100 SunOS solaris 5.11 11.2 i86pc 10/31/2015 11:54:38 runq-sz %runocc swpq-sz %swpocc 11:54:39 0.0 0 0.0 0 11:54:40 0.0 0 0.0 0 11:54:41 0.0 0 0.0 0 11:54:42 0.0 0 0.0 0
- How to Check Free memory with sar for Oracle Solaris?
- Freeswap:freeswap*512 bytes
#pagesize 4096
casesup@solaris:~$ sar -r 1 100 SunOS solaris 5.11 11.2 i86pc 10/31/2015 11:57:26 freemem freeswap 11:57:27 435698 6381072 11:57:28 435697 6381072 11:57:29 435699 6381072 11:57:30 435700 6381072
- How to check swap activity with sar for Oracle Solaris?
- swpot/s:The avarage number of process swapped out. This is too critical. You need to check if it’s bigger then “1”. Then you need to increase system memory.
CPU Usage Controls:
- How to check Idle CPU with sar for Oracle Solaris?
- “sar -u” command shows the processors is either busy or free.When processor is busy it means that the processor is in either user mode or system mode. I remommend to check first idle cpu if it’s too low then check system mode or user mode.
- %usr:User mode
- %sys:System mode
- %wio:Waiting for I/O
- %idle:Idle not waiting for I/O
- “sar -u” command shows the processors is either busy or free.When processor is busy it means that the processor is in either user mode or system mode. I remommend to check first idle cpu if it’s too low then check system mode or user mode.
casesup@solaris:~$ sar -u 1 10 SunOS solaris 5.11 11.2 i86pc 11/01/2015 08:10:07 %usr %sys %wio %idle 08:10:08 5 14 0 81 08:10:09 6 18 0 76 08:10:10 4 2 0 94 08:10:11 4 2 0 94
Disk Usage Controls:
- How to check disk service time or utulization with sar command for Oracle Solaris?
- avserv:Avarage time,in milisecond, that I/O request wait for idle in the queue.
- avwait :Avarage time,in milisecond, that I/O request to be completed by disk device.This is importand and also depends on your Storage luns. For mission critical systems and SSD disk this parameter can be observed max “10”.
casesup@solaris:~$ sar -d 1 100 SunOS solaris 5.11 11.2 i86pc 11/01/2015 08:27:34 device %busy avque r+w/s blks/s avwait avserv 08:27:35 ata1 0 0.0 0 0 0.0 0.0 iscsi0 0 0.0 0 0 0.0 0.0 mpt0 1 0.0 71 2367 0.0 0.5 scsi_vhc 0 0.0 0 0 0.0 0.0 sd0 1 0.0 73 2367 0.0 0.5 sd0,a 0 0.0 2 0 0.0 0.0 sd0,b 1 0.0 71 2367 0.0 0.5 sd0,h 0 0.0 0 0 0.0 0.0 sd0,i 0 0.0 0 0 0.0 0.0 sd0,q 0 0.0 0 0 0.0 0.0 sd0,r 0 0.0 0 0 0.0 0.0 sd1 0 0.0 0 0 0.0 0.0
