Comment 2 for bug 1680316

Why do you consider the CPU usage to be abnormal?

pbzip2 is a parallel bzip2 utility which allows to engage more of the CPU power in compression/decompression activities (so that it runs faster). High CPU usage is in general not something abnormal.

There is a -p flag which you may use to set the number of worker threads to use (if not explicitly set - by default that's equal to the number of your CPUs). As far as I see from the screenshot - there is some kind of backup running (the tar processes) in at least 2 processes (it means it's engaging 2 x #CPUs threads).

So you can tweak that backup - by specifying a different -p# for pbzip2, or to run in single thread - switch to plain bzip2, or you may change the priority of the process.

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Maybe not related to the issue, but I also see you're using a bit old version of pbzip2. You may find the latest release at https://launchpad.net/pbzip2