Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Asvc_t values in iostat output
Operating Systems Solaris Asvc_t values in iostat output Post 302948567 by jim mcnamara on Tuesday 30th of June 2015 01:03:28 PM
Old 06-30-2015
The ascv_t time varies all over the place. A SATA 7200rpm disk will be saturated at a lower asvc_t number than a disk with higher rpms.

The point is that those numbers are relative. You have to work with them under various system conditions to really understand what you are seeing. MadeInGermany is giving a good start, but do not jump onto 'fixing' things until you are sure you understand the problems. It could simply be a poorly written piece of code eating a disk for lunch.

That 25 number is mostly baloney. IMO. I have a SAN with huge IOPS capacity. A number like 24 would indicate an unbelievably high load. I could see that by looking at r/s and w/s for that disk. On some other device, it is okay.

If you need help with tuning, consider sarcheck - it does a good job of sroting through sar data and telling you what is happening. IMO
 

10 More Discussions You Might Find Interesting

1. Solaris

iostat -e / -E output explanation

Hi all, hope you are having a nice day, its nice and warm today in Canberra Australia. iostat -e / -E reports soft and hard errors. Any idea what these are exactly? All I hear are I/O's failing and needing to retry, but no cause as to why they fail. My SUN guru tells me its our EMC SAN... (1 Reply)
Discussion started by: scottman
1 Replies

2. UNIX for Advanced & Expert Users

iostat output what is that mean

Hi all, i have run iostat -em, and get below result. Can i know what is this output meaning, and how to fix that problem. iostat -em ---- errors --- device s/w h/w trn tot sd7 0 1 0 1 sd8 1 1 0 2 sd9 0 1 0 1 sd10 0 ... (2 Replies)
Discussion started by: foongkt5220
2 Replies

3. UNIX for Dummies Questions & Answers

sar and iostat recommended interval/count values.

Hi, I got a request from a client to check on their server's cpu, memory and disk utilization. Am planning to use the sar and iostat commands to achieve this. The server is used for sending and receiving messages between the stockbrokers, so I was thinking to run the commands during the market... (9 Replies)
Discussion started by: 60doses
9 Replies

4. Shell Programming and Scripting

Formatting output from iostat

So I use Cacti for monitoring IO statistics on my servers, now originally I couldnt monitor Multipath deviced servers as they have alot of /dev/sdxx and /dev/emcpowerxx, I have devised a method of trimming them down to just the actual devices but the issue is the output looks like so. # iostat... (0 Replies)
Discussion started by: RiSk
0 Replies

5. Shell Programming and Scripting

summing up iostat values in AIX

Friends, I have to run iostat -d on my AIX machine and print the sum of the output in tps column per iteration. can any one pls guide me how to do this using awk. here is the sample output iostat -d 2 2 | awk '!/System/ && !/Disks/ && !/cd/ && !/^$/ {print $4}' 2.0 3.0 1.0 3.0... (1 Reply)
Discussion started by: achak01
1 Replies

6. Shell Programming and Scripting

finding greatest value in a column using awk from iostat output in linux

Friends, . On linux i have to run iostat command and in each iteration have to print the greatest value in each column. e.g iostat -dt -kx 2 2 | awk ' !/sd/ &&!/%util/ && !/Time/ && !/Linux/ {print $12}' 4.38 0.00 0.00 0.00 What i would like to print is only the... (3 Replies)
Discussion started by: achak01
3 Replies

7. Shell Programming and Scripting

finding greatest value in a column using awk from iostat output in linux

Friends, Need some help. On linux i have to run iostat command and in each iteration have to print the greatest value in each column. e.g iostat -dt -kx 2 2 | awk ' !/sd/ &&!/%util/ && !/Time/ && !/Linux/ {print $12}' 4.38 0.00 0.00 0.00 WHhat i would like to... (15 Replies)
Discussion started by: achak01
15 Replies

8. Filesystems, Disks and Memory

iostat output vs TPC output (array layer)

Hi Guys, I've been having some arguments with my colleagues about one thing. Always my thought was that as as far as disk performance is concern by looking at the output of the iostat command (AIX) you would be able to identify if you have a hot disk and then by moving some files out that disk... (3 Replies)
Discussion started by: arizah
3 Replies

9. Solaris

Unmatched ssd create huge unuseful iostat output

My scheduled collection of statistics is giving very large output because of an high number of ssd device not associated to any disk The iostat -x command is collecting statistics from them and the output is very large. I.g. if a run iostat -x|tail +3|awk '{print $1}'>f0.txt.$$ iostat... (5 Replies)
Discussion started by: sun-mik
5 Replies

10. Shell Programming and Scripting

Need help to parse iostat command output

Hi, I got the code below is one of the threads from this forum. lineCount=$(iostat | wc -l) numDevices=$(expr $lineCount - 7); iostat $interval -x -t | awk -v awkCpuFile=$cpuFile -v awkDeviceFile=$deviceFile -v awkNumDevices=$numDevices ' BEGIN { print... (2 Replies)
Discussion started by: gopivallabha
2 Replies

LEARN ABOUT ULTRIX

iostat

iostat(1)						      General Commands Manual							 iostat(1)

Name
       iostat - report I/O statistics

Syntax
       iostat [ -c ] [ -t ] [ disknames ] [ interval ] [ count ]

Description
       The  command  reports  I/O  statistics for terminals, disks and cpus.  For terminals the number of input and output characters are counted.
       For disks the number of 512 byte blocks per second and number of transfers per second are displayed.  For cpus, it provides the	percentage
       of  time  the system has spent in user mode, in user mode running low priority (niced) processes, in system mode, and idling.  On multipro-
       cessor systems these cpu statistics represent a cumulative summary of all the cpus.

       The optional disknames argument causes disk statistics to be displayed for the specified disks.	If this argument  is  not  specified  then
       disk statistics will be displayed for the first 3 disks only.

       The  optional interval argument causes to report once each interval seconds.  The first report is for all time since a reboot and each sub-
       sequent report is for the last interval only.

       The optional count argument restricts the number of reports.

Options
       -c   Displays the percentage of time each cpu spent in user mode, running low priority (nice'd) processes, in system mode, and idling.

       -t   Displays the number of characters read from and written to terminals.

Examples
       This example will cause cpu and disk statistics for the 5 disks ra0, ra1, ra2, ra3, and ra4.
	    iostat ra0 ra1 ra2 ra3 ra4
       This example will cause cpu, terminal, and disk statistics for ra0 to be displayed and updated every 2 seconds.
	    iostat -t ra0 2

Files
See Also
       vmstat(1), cpustat(1)

																	 iostat(1)
All times are GMT -4. The time now is 12:46 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy