mount, findmnt,df命令

■    The  mount  command gives an overview of all mounted devices. To get this information, the /proc/mounts file is read, where the kernel keeps information about all current mounts. It shows kernel interfaces also, which may lead to a long list of mounted devices being displayed.

■   The  df -Th  command was designed to show available disk space on mounted devices; it includes most of the system mounts. Because it will look on all mounted file systems, it is a convenient command to get an overview of current system mounts. The  -h  option summarizes the output of the command in a human-readable way, and the  -T  option shows which file system type is used on the different mounts.    

The output of  df  is shown in seven columns:    
■    Filesystem:     The name of the device file that interacts with the disk device that is used. The real devices in the output start with /dev (which refers to the directory that is used to store device files). You can also see a couple of tmpfs devices. These are kernel devices that are used to create a temporary file system in RAM.    
■    Type:     The type of file system that was used.    
■    Size:     The size of the mounted device.    
■    Used:     The amount of disk space the device has in use.    
■    Avail:     The amount of unused disk space.    
■    Use%:     The percentage of the device that currently is in use.    
■    Mounted on:     The directory the device currently is mounted on.      
Note that when using the  df  command, the sizes are reported in kibibytes. The option  -m  will display these in mebibytes, and using  -h  will use a human-readable format in KiB, MiB, GiB, TiB, or PiB.

■   The  findmnt  command shows mounts and the relation that exists between the different mounts. Because the output of the  mount  command is a bit overwhelming, you may like the output of  findmnt .  Listing   3.2    shows sample output of this command.