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internal disk causing high%wio

Super Advisor

internal disk causing high%wio

Hi All!


I have a system that runs 11.31 and oracle 11, and an application. Whenever I start the app, the %wio shoots up and by doing  sar -d 5 5 5, I noticed that "disk1" which is the internal drives have the "avwait" column bigger that the "avserv", so this indicates to me that something is not right with either the disks, or oracle and the app that are installed on the internal drives (/opt)


Is my assumption correct?


Please can I have your comments



Honored Contributor

Re: internal disk causing high%wio

It just means the disk is requested to perform more I/O operations than it can do, so queueing happens.


What are the r+w/s and blks/s values like when you experience high avwait times?


Do you have application data on "disk1"? If so, putting it on a different storage with more IOPS should give you better performance.


Having just the oracle and/or application binaries on the system disk might not be so bad, as the number of I/O operations should go down after the application has completed start-up and stabilized.


Super Advisor

Re: internal disk causing high%wio


Hi, thanks for the reply, I only noticed that kind of behaviour when I start the application, after some time, drops down.

The data is on external storage,only binaries are on internal disks.