Following are the operating tools:
User Management
Security policy
Device Management
Performance Monitor
Task Scheduler
A) User management:
User management includes everything from creating a user to deleting a user on your system. User management can be done in three ways on a Linux system.
Command line tools include commands like useradd, userdel, usermod, passwd, etc. These are mostly used by the server administrators.
Useradd: With useradd commands you can add a user.
Syntax: useradd -m -d /home/<userName> -
c "<userName>" <userName>
Example: useradd -m -d /home/xyz -c "xyz" xyz
File /etc/default/useradd contains some user default options.
The command useradd -D can be used to display this file.
Syntax: useradd -D
Userdel: To delete a user account userdel command is used.
Syntax: userdel -r <userName>
Usermod: The command usermod is used to modify the properties of an existing user.
Syntax: usermod -c <'newName'> <oldName>
Example: usermod -c 'vppoly' john
Using passwd command
Passwd: A user can set the password with the command passwd. Old password has to be typed twice before entering the new one.
Syntax: passwd <userName>
Example: passwd vppoly
B) Device Management:
Device management is the process of managing the implementation, operation and maintenance of a physical and/or virtual device.
All Linux device files are located in the /dev directory, which is an integral part of the root (/) filesystem because these device files must be available to the operating system during the boot process.
Example: ls –l /dev
Above example gives the list of device file from kernel.
Udev supplies a dynamic device directory containing only the nodes for devices which are connected to the system. It creates or removes the device node files in the /dev directory.
C) Performance Monitor:
It is very tough job for every system or network administrator to monitor and debug Linux System Performance problems every day.
The commands discussed below are some of the most fundamental commands when it comes to system analysis and debugging Linux
server issues such as:
1) vmstat: Virtual memory statistics
The vmstat command reports information about processes, memory, paging, block IO, traps, and cpu activity.
$ vmstat 3
2)top: Process activity monitoring command top command display Linux processes. It provides a dynamic real-time view of a running system i.e. actual process activity. By default, it displays the most CPU-intensive tasks running on the server and updates the list every five seconds.
$ top
3) free: Show Linux server memory usage free command shows the total amount of free and used physical and swap memory in the system, as well as the buffers used by the kernel.
# free
4) iostat: Montor Linux average CPU load and disk activity iostat command report Central Processing Unit (CPU) statistics and input/output statistics for devices, partitions and network filesystems (NFS).
# iostat
5) netstat Linux network and statistics monitoring tool netstat command displays network connections, routing tables, interface statistics, masquerade connections, and multicast memberships.
# netstat –tulpn