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As an administrator, you will also need to keep track of available disk space on your

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disks.

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So let's have a look at the commands that are involved.

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To start with, there is the df command.

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Df shows the amount of space that is available on mounted devices.

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It has different options to determine how you want to see it displayed.

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Then there is du, which stands for disk usage.

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It's giving a summary, and the nice thing about it is that you can see how much files

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you've got in a specific directory.

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Now you should notice that these utilities don't work very well on thin provisioned storage,

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and that is because thin provisioned storage is pretending to offer more storage than is

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really available.

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So you might see 20 GB available, where in reality, after writing 5 GB, your thin provisioned

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storage might be full.

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Let me demonstrate these tools.

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So let's use df minus h to start with.

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I like the option minus h, because minus h is giving a human-readable format.

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So here we can see the most important storage device, which is the LVM Logical Volume Root

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on the volume group CS, and it has 13 GB available.

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Otherwise, we can see that there is the boot device with 606 MB available.

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I just said gigabyte, really it's gigabyte, because gibi, mebi, and so on is the default

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display in anything regarding your storage.

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Now if you want to see how much files in a directory, use du minus hs on USR, for instance.

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Then it needs to calculate a little bit, and here we can see that USR in total has 3.8

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GB of storage available.

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And that's how you monitor available disk space.