Which command would you use to check the filesystem's disk usage statistics?

The command used to check the filesystem's disk usage statistics is the "du" command. This command is utilized to estimate and report the disk space used by files and directories. When executed, "du" provides a summary of disk usage for a specified directory or file, recursing through subdirectories to give a more comprehensive view of how much disk space is consumed.

In contrast, the other commands listed serve different purposes:

• "iostat" is primarily used for monitoring system input/output device loading by observing the time devices are active in relation to their average transfer rates, but it does not provide filesystem-specific disk usage statistics.
• "blkid" is used to locate or print block device attributes, like UUID or filesystem type, providing details about disk devices rather than their usage.
• "mount" is a command to attach filesystems to the system's file hierarchy and does not show information about disk usage statistics.

Using "du" is the appropriate choice for evaluating how much disk space is currently being utilized by files and directories in a filesystem.