/DEV/SR0 CD-ROM mount caused CPU io_wait rise a "murder"

Regular patrol found a strange problem,/dev/sr0 CD-ROM mount caused by the CPU io_wait rise, see:

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Near the early morning, this time there is no business, you can see the CPU's US usage is already 0, but the CPU 12th core appeared 100.0%wa,load load is 1.0, too weird.

Immediately with the Iotop command to see which process consumes IO too high, found the Mount CD-ROM caused by the real killer, see:

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It is obvious that the/DEV/SR0 optical drive consumes a lot of IO operations.

View the system log and find the error message:

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It is again determined that the CPU io_wait raised by the/DEV/SR0 mounted optical drive.

Immediately release the big strokes, dry ya:

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Observe the cacti monitor chart again:

650) this.width=650; "src=" http://s3.51cto.com/wyfs02/M00/74/02/wKiom1YMEJvCi55FAAKujqKaBNE349.jpg "title=" 5.png " alt= "Wkiom1ymejvci55faakujqkabne349.jpg"/>

The CPU load has dropped, and it's very obvious to see.

This article is from the "Spring Yang Technical column" blog, please be sure to keep this source http://hcymysql.blog.51cto.com/5223301/1699703

/DEV/SR0 CD-ROM mount caused CPU io_wait rise a "murder"