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Questions tagged [iostat]

90 questions
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iostat showing wait queue when device is not 100% busy

I am on Solaris 11 and I am seeing the following %w=32 %b=62 extended device statistics r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device 47.5 2564.6 1460.1 33481.8 62.1 93.0 23.8 35.6 **32 62**…
Noob
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Linux "iostat" to .csv file using Perl

I am experimenting with the iostat -c 1 command, and I was wondering if there is a simple way of reading the current output and then separating the values so that I could generate a .csv file. The goal is to be able to generate graphs, using the…
Malaco
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NFS read/writes since startup

I'd like to retrieve the total number of kilobytes read/written for each NFS mount point. Using the following commands, I'm able to see the current throughput for each NFS mount point in kB/S. iostat -nk Alternatively: nfsiostat Is there a way to…
Fidel
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How many milliseconds of await is considered to be high?

How many milliseconds of await is considered to be high? i have 800ms and 600ms iostat -x avg-cpu: %user %nice %system %iowait %steal %idle 1.28 0.00 0.22 0.90 0.00 97.60 Device: rrqm/s wrqm/s r/s w/s …
Gabriel Sousa
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How to interpret iostat for a crumbling MySQL server

We have a combined application/MySQL-server which has started to crumble. Right now, it gets stuck on copying a 125 million row MySQL MyISAM table (INSERT INTO a_copy SELECT * FROM a with KEYS DISABLED on a_copy). We've benchmarked the job of which…
Henrik Lindberg
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What is the difference between rMB_nor/s, rMB_dir/s, and rMB_svr/s in iostat?

I'm trying to interpret the results of running the following command iostat -mnhyc It produces the following Filesystem: rMB_nor/s wMB_nor/s rMB_dir/s wMB_dir/s rMB_svr/s wMB_svr/s ops/s rops/s …
adhanlon
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slow file server with contradictory values for CPU and CPL in atop

I've got a fileserver (centos 6.3) that slowed down suddenly earlier today. The cluster that mounts it could access other NFS mounts without a problem, but the access to this one was VERY slow. Logging on via ssh was very slow too (and the idrac…
Michael S
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Strange iostat numbers

I'm experiencing unusual load issue on one of our VM which is on SAN storage. As a general practice I ran iostat on the server got very strange numbers. avg-cpu: %user %nice %system %iowait %steal %idle 0.00 0.00 0.17 …
vasco.debian
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iostat to analyze iSCSI mount

Is there a way to analyze the IO wait on a iSCSI mount from the machine on which the iSCSI share is mounted? I understand the local volumes can be analyzed, but, we have one particular directory on which the iSCSI storage is mounted. I'm interested…
venkrao
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MySql/RedHat, High I/O Wait ... for a few hours... then disappears

I've got a RH server as a VMWare instance logging GPS fixes 24x7. The transaction volume hasn't changed over the months (in fact I am pruning the transaction table more aggressively now) with only 600k to 800k records at a given time. There are no…
Tim Nelson
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CPU Usage vs load average

I'm running debian iostat -x Linux 2.6.32-5-amd64 (server56856.uk2net.com) 27/04/13 _x86_64_ (4 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 4.59 0.01 1.08 2.46 0.00 91.85 Device: …
Juddling
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Averaging dstat output

I need to average upload and download speed using dstat -n. How can I add all the received and sent datas that appear after dstat -n, so that I can add them and find average upload and download speed over some period of time?
Optimus Prime
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No apparent reason for high load average

We have several web servers running on Amazon (ec2) c1.xlarge, over Amazon AMI. The servers are duplicates of each other, running the exact same hardware and software. Each server spec is: 7 GB of memory 20 EC2 Compute Units (8 virtual cores with…
Oz.
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Finding throuput of CPU and Hardrive on Solaris

How do I find the throughput of a CPU and the hard disk on an OpenSolaris machine? Using mpstat or iostat? I'm having a hard time identifying the throughput if it is given at all in the commands output. For example, in mpstat there is very little…
Jim
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Is iostat unreliable?

I have noticed something worrying with iostat that I can't quite explain - it appears iostat may not be quite reliable(?) I'm trying to troubleshoot poor MySQL performance, and one ovious place to look is the disks, so: ip-10-14-4-14 root : iostat…
j4nd3r53n
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