Red Hat Certified Engineer (RHCE) Interview Questions & Answers

Question 1. What Command Do You Use To Format A Partition With A File System?

Answer :

You could use mkfs command to format partition with file system.

Question 2. Which Command Will Assign Ip Address 192.168.1.1 And Subnet Mask 255.255.255.0 To Eth0 Network Interface?

Answer :

Ifconfig command can be used to assign IP address. Following command will do the given task. Ifconfig eth0 192.168.1.1 net mask 255.255.255.0

Question 3. Which Option In Fdisk Will Display The Partition Table?

Answer :

In fdisk utility, the "p" command will print the partition table.

Question 4. To Create A Recurring Scheduled Task, Which Linux Scheduling Tool Should You Use?

Answer :

The cron command allows you to create recurring tasks.

Question 5. What Command Can You Use To Enable An Ethernet Network Interface That Has Already Been Configured?

Answer :

To enable already configured interface use Ifconfig [interface] up command. For example to up eth0 interface use following command.

#Ifconfig eth0 up

Question 6. How Will You Decompress The Demo.tar.gz File?

Answer :

To decompress use following command

#tar -zxvf demo.tar.gz

Question 7. A Core Dump File Contains This Message, “program Terminated With Signal 11, Segmentation Fault.” What Does This Message Indicate?

Answer :

The core file will tell you what exactly caused the program to crash. So this message indicates that the program crashed because of a segmentation fault in memory.

Question 8. What Command Runs Fdisk On The First Ata/ide Hard Drive?

Answer :

The first ATA/IDE hard drive is hda, so the command would be

# fdisk /dev/hda

Question 9. An Application Is Creating Several, Very Large Core Dump Files. What Should The Administrator Do If He Has No Intention Of Debugging These Files?

Answer :

If administrators have no intention of keeping these files for debugging purposes, they should be deleted because they are wasting valuable disk space, and may cause system to run out of space.

Question 10. When Checking The Partition Information On Your Hard Drive With Fdisk, You Notice That One Of The Partitions Is Formatted As "linux Swap" And Is Approximately 512mb In Size. What Is The Purpose Of This Partition?

Answer :

The Linux swap file is used for virtual memory to store additional information that cannot fit into current memory. This swap file allows information to be cached on disk, and can be retrieved very quickly. Heavy use of the swap file indicates a low memory condition.

Question 11. What Sort Of Kernel Error Can Cause A Linux System To Crash And Write A Memory Core Dump?

Answer :

Kernel panic error can cause a Linux system to crash. A kernel panic indicates that a kernel process has crashed. This is a very serious error that causes the entire Linux system to crash. These core dumps should be analyzed carefully to find the root cause of the problem.

Question 12. An Administrator Wants To Assign An Ip Address Of 192.168.1.10, A Subnet Mask Of 255.255.255.0, And A Broadcast Address Of 192.168.1.254 To Eth1. What Command Will Accomplish This Task?

Answer :

Following command will do this task. Ifconfig eth1 192.168.1.10 net mask 255.255.255.0 broadcast 192.168.1.254.

Question 13. You Are Tasked To Set Up A Schedule To Perform Automatic Checks Of Available Disk Space At The End Of The Day. How Can You Accomplish This Task?

Answer :

To accomplish this task set up cron to run a script that will check the disk space daily at 7:00 p.m. The output will be e-mailed to the root account. You can compare the results from day to day to analyze disk space usage.

Your cron file should look similar to the following:

* 19 * * * df -kl.

Question 14. As A Administrator You Need To Terminate The Send Mail Process. How Will You Do That?

Answer :

First you need to determine the PID of send mail so it can be killed.

#ps -ef |grep send mail

Now you can use kill command to terminate the process associated with send mail.

Question 15. You Noticed A Kernel Error Message During The Boot Process, But It Scrolled Before You Could Read This? What Log File Could You Check To Find Out That Message?

Answer :

The log file that contains kernel boot messages is /var/log/dmesg.

Question 16. You Execute A Command That Is Going To Take A Long Time. How Can You Get Back To Your Shell Prompt To Perform Other Task?

Answer :

You can use bg command to send a running process to the background.

Question 17. You Need To Kill All Instances Of Web Server? What Command Will You Execute To Do This?

Answer :

You can use killall httpd command to kill all httpd process. httpd process run web server.

Question 18. How Can You List All Running Process?

Answer :

Use ps -ef command to list all running process.

#ps -ef

Question 19. As A Linux Admin You Want To Know What Processes Are Being Run By User Sumit. What Command Can You Use?

Answer :

You can use #ps -au command to list all the process owned by user. Following command will do the assigned task

#ps -au summit

Question 20. Which Log File Keeps Track Of All User Logins And Logouts?

Answer :

/var/log/wtmp log file keeps track of all user logins and logouts.

Question 21. What Is The First Process That Is Run When A Linux System Starts, And Is Responsible For Starting All Other System Processes And Services?

Answer :

The init process is the first process to be run. It is the parent process of all other Linux system processes, services, and daemons that are needed to run the system.

Question 22. Which Command Will You Use To Bring A Process In Foreground, Which Is Running In The Background?

Answer :

The fg command immediately moves the program to the foreground.

Question 23. An Administrator Has Accidentally Killed A Core Process. What Is The Result Of This Action?

Answer :

Killing a core process can potentially crash your system because many critical services rely on these core processes.

Question 24. As A Administrator You Need To Monitor The /var/log/messages File In Real Time To Resolve The Issue? How Would You Do That?

Answer :

You can use tail command with -f option. Following command will do the assigned task

#tail -f /var/log/messages

Question 25. From The Output Of Ps Command How Will You Determine The Id Number Of The Parent Process Of A Particular Program?

Answer :

PPID refers to the parent process identification number.

Question 26. While Scanning The /var/log/messages File, You Notice An Error Stating An Authentication Failure For Root. What Could This Mean?

Answer :

Any failed login attempts for root are logged into the /var/log/messages file. It indicate that some has tried to login as root.

Question 27. As An Administrator You Noticed From Top Command That An Unidentified Process Is Using Up All Cpu And Memory. You Suspects That Is A User's Process That Has Run Away. How Should You Fix This?

Answer :

The process should be immediately killed before it consumes so many resources that the server cannot run properly and therefore crash.

Question 28. What Command Can An Administrator Use To Track Real-time Information On Processes And The Resources That They Are Using?

Answer :

The top command is used to monitor processes and resources in real-time.

Question 29. A Developer With Username Sanjay Has Told You That One Or His Processes Seem To Be Locked Up And He Cannot It. He Reported That It A Bug In His Code And May Quickly Use Up All Cpu And Ram Resources On The Server. How Will You Tack The Process And Terminate It?

Answer :

Your first step is to identify the process, use ps command

#ps -au sanjay

Now run top command to compare the process running, and verify which one is using the most resources. After you have identified the problem process, you can use the kill command to terminate it. Because the user was unable to stop the process, you should probably force a kill signal to make sure that the process stops:

#kills -9 [PID of process]

Now, to verify that it has stopped, run the ps command again on the user:

ps -au sanjay

Question 30. What Is Kerberos Used For?

Answer :

Kerberos is used for secure network logon.

Question 31. Which Partition Store System Configuration Files In Linux System?

Answer :

/etc partition stores system configuration files in Linux.

Question 32. What Is The Purpose Of The Md5 Option On Passwords?

Answer :

MD5 is an encryption method that encrypts the password before saving.

A better method of password security is to create difficult-to-break passwords that are easy for the users to remember.

Question 33. What Is The Alternative Method To A Gui Installation In Linux?

Answer :

Linux provides text base installation as the alternative method of GUI installation.

Question 34. What Is The Purpose Of The Swap On Command?

Answer :

Swap on command is used to activate a already created swap partition. It cannot be used to create a new swap partition.

Question 35. What Is Gzip?

Answer :

Gzip is a compression utility created by the GNU project.

Question 36. Name Any Four General Password Rules For User Account?

Answer :

• Include at least eight total characters.
• Use the string in an unrepeated way.
• Avoid use words that can be found in the dictionary..
• Avoid use dates of significance, such as a birthday or anniversary.

Question 37. What Is Tar?

Answer :

Tar is an archive utility that is used to create tape backups.

Question 38. Which Is The Standard Command Used To Uncompress Gzip Files?

Answer :

The standard command used to uncompress gzip files in gunzip.

Question 39. What Is The Rpm Switch For Only Installing Packages?

Answer :

The command line switch for installing an RPM is -i.

Question 40. What Is The Command Used To Install An Rpm Package Named Demo Filename 2.2-2.i386.rpm?

Answer :

The most common command used to install an RPM package is rpm -ivh. Following command will install the given package

#rpm -ivh demo filename 2.2-2.i386.rpm

Question 41. What Is The Command Used To Remove An Rpm Package Named Demofilename2.2-2.i386.rpm?

Answer :

The most common command used to remove an RPM package is rpm -evh. Following command will remove the given package

#rpm -evh demofilename2.2-2.i386.rpm

Question 42. What Is The Command Used To Update An Rpm Package Named Demofilename2.2-2.i386.rpm?

Answer :

The most common command used to update an RPM package is rpm -Uvh. Following command will update the given package and remove the old.

#rpm -Uvh demofilename2.2-2.i386.rpm

Question 43. Where Is The Automatically Mounted File Systems Listed?

Answer :

The automatically mounted file systems are listed in the file /etc/fstab.

Question 44. While Installing The New Rpm What Common Steps Should Take?

Answer :

You should follow these common steps:

• Use RPM tools should be used to query or verify the installed packages to.
• Confirm the installation of any previous packages.
• Check the signature of new package.
• RPM should be installed or upgraded by first using the test mode to verify that it works, and then it should be installed.
• At the end query the RPM and verify the installation of RPM.

Question 45. Which Organization Controls The Official Releases And Updates Of The X Window System?

Answer :

The X Consortium at www.x.org controls the official release and updating of the X Window System.

Question 46. Ppp Is Most Often Used To Create?

Answer :

PPP is most often used to create serial point-to-point connections.

Question 47. What Command Is Used To Load A Module Into The Kernel?

Answer :

The insmod command is used to load a module into the kernel.

Question 48. With Respect To A Linux System’s Ram, How Large Should The Swap File Be?

Answer :

Generally the size of the swap file should be twice the size of installed RAM.

Question 49. How Would You Create A Backup Of The Fstab File To The /backup Folder?

Answer :

Use cp command to create the backup.

#cp /etc/fstab /backup

Question 50. What Command Is Used To Exit The Edit Mode Of Vi Editor?

Answer :

The [esc] key is used to exit from the edit mode of VI editor.