Ans: The df command displays the amount of disk space occupied by mounted or unmounted file systems, the amount used and available space, and how much of the file system's total capacity has been used. The file system is specified by device, or by referring to a file or directory.

The disk usage (du) command outputs the number of kilobytes used by each subdirectory on current path. Useful if you have gone over quota and you want to find out which directory has the most files.

Ans: Unix identifies each process with a unique integer called ProcessID. The process that executes the request for creation of a process is called the 'parent process' whose PID is 'Parent Process ID'. Every process is associated ...  

Ans: Swapping: Whole process is moved from the swap device to the main memory for execution. Process size must be less than or equal to the available main memory. It is easier to implementation and overhead to the system. Swappi...  

Ans: By using “df”
command in UNIX. For example “df -h.” will list how full your current
drive is.

Ans: By using “top” command in UNIX.

Ans: Many options but you can say by using “scp” command.

Ans: use history command along with grep to find any relevant command you have already executed.

Ans: by using either ping or telnet command in UNIX.

Ans: For running a process  in background use “&” in command line. For bringing it back in foreground use command “fg jobid” and for getting job id you use command “jobs”, for  killing that process find PID and use kill -9 PID command.

Ans: Either by using
“uname -a” command or by using “arch” command.