Enabling Network Interface eth0
Login as root and execute the command at the terminal to bring up eth0
The system would determine an IP address for interface eth0 and return a prompt.
Now, type a command
to view the configuration on a currently active interfaces and the loopback interface. The command is used to configure the kernel-resident network interfaces. If interface name is given as an argument, the details of the that specific interface displayed
Display all interfaces details including disabled interfaces
Enable an Interface
ifconfig eth0 up
Disable an Interface
ifconfig eth0 down
Assign IP address to an Interface
ifconfig eth0 22.214.171.124
ifconfig eth0 mtu XX
The DHCP dynamically assign an IP address to eth0 on the system.
Fedora tested new Linux Network device naming scheme, as implemented by the biosdevname utility provided by Dell. It would give network interfaces names that are both consistent and appropriate to their physical attributes.
who [options] [filename]
To find out the time of last system boot, current run level of the system and list of logged in users and more.
To get the information about currently logged in user on the system which includes login name, terminal line numbers, login time, remote host name
Get the list of users logged in to system
Details of the current logged in user
Get system's username
Get user identification information
Get the count of users logged on to system
who -q -H
Get hostname and user associated with standard input such as a keyboard
who -m -H
Display all active processes which are spawned by INIT process
who -p -H
Find status of the user's message as +, – or?
who -T -H
Last boot time of the system
who -b -H
Get the details of all dead processes
who -d -H
System login process details
who -l -H
Current run level of the system
To find out how long the system is active or running. It displays the current time, amount of system is in running state, the number of users currently logged, load time for the pat 1, 5 and 15 minutes respectively.
-p, –pretty show uptime in pretty format i.e., human readable format
-h, –help display this help and exit
-s, –since system up since when the system started running
-V, –version output version information and exit
Get the list of users and their activities
It's a combination of uptime and who commands given one immediately after the other.
top [-b] [-nCOUNT] [-dSECONDS] [-m]
Displays system and processes information as:
- First Row show: current time, uptime of the machine, users sessions logged in, and average load on the system to the last minute, five minutes and 15 minutes respectively.
- Second Row: Total Processes running, Running Processes, Sleeping Processes, Stopped Processes, Processes waiting to be stopped from the parent process
- Third Row : cpu usage percentage(%'s) as User processes of CPU, System processes of CPU, Priority upgrade nice of CPU, Percentage of the CPU not used, Processes waiting for I/O operations of CPU, Serving hardware interrupts of CPU, Percentage of the CPU serving software interrupts
- Fourth and Fifth Row: Memory usage, total memory in use, free, buffers cached.
- Sixth Row: Processes List running currently. Let’s see what information we can observe in the different columns.
PID – ID of the process
USER – The user that is the owner of the process (root)
PR – priority of the process
NI – The “NICE” value of the process
VIRT – virtual memory used by the process
RES – physical memory used from the process
SHR – shared memory of the process
S – indicates the status of the process: S=sleep R=running Z=zombie (S)
%CPU – This is the percentage of CPU used by this process
%MEM – This is the percentage of RAM used by the process
TIME+ –This is the total time of activity of this process
COMMAND – And this is the name of the process
rsync options source destination
For copying and synchronizing files and directories locally as well as remotely. It is used to perform data backups and mirroring between two Linux machines. It copies the whole content of a file or a directory from source to destination and from next time, copies only the changed blocks and bytes to the target.
-v : verbose
-r : copies data recursively (but don’t preserve timestamps and permission while transferring data
-a : archive mode, archive mode allows copying files recursively and it also preserves symbolic links, file permissions, user & group ownerships and timestamps
-z : compress file data
-h : human-readable, output numbers in a human-readable format