Which command is used to check disk space on a Linux-based Avanti server?

The command used to check disk space on a Linux-based Avanti server is 'df -h'. This command reports the amount of disk space used and available on file systems in a human-readable format. The '-h' flag stands for "human-readable," which makes it easier for users to interpret the output by converting the sizes into easily understandable units (like GB or MB).

When executed, 'df -h' will display a list of all mounted file systems along with their total size, used space, available space, and the percentage of space used. This information is crucial for system administrators who need to monitor disk space utilization to ensure that the server runs smoothly and to avoid issues related to insufficient disk space.

The other choices are not appropriate for checking disk space. 'ls -l' lists files and directories in a specified directory with detailed information but does not provide disk usage statistics. 'diskusage' is not a standard command found in Linux for checking disk space—there's a command called 'du' that can show disk usage for specific directories, but it's not used in the same way as 'df'. Lastly, 'checkdisk' is a command used in Windows for checking disk errors and is not applicable in a Linux environment.