Test your basic knowledge |

RHCSA

Subjects : certifications, it-skills, rhcsa

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. Most boot issues can be resolved by...
entering rescue mode and repairing the problem.
You add your action to the end of the /home/user01/.bashrc file.
browseable option
You can use the remove or erase options with yum to remove a package.

2. The exportfs command is used to...
schedule one-time-only jobs
export one or all resources
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
user's home directory in the /etc/skel directory

3. What is a gateway used for on a network?
When the system starts up again - the cron service will run any jobs that were missed while the system was off. On Red Hat Enterprise Linux 5 - the anacron service handles this functionality.
A gateway is used as an entry and exit point for a subnet on a network. To contact hosts outside your subnet - you need to pass through a gateway.
Using the chcon command - you can change the context of a file to work with Apache.
If you shrink a volume group or logical volume - there is a chance you could lose data depending on how much you shrink the volume.

4. How can you list all services on the system to tell whether they will boot during startup?
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
Physical volumes - volume groups - and logical volumes.
chkconfig—list

5. What command is used to change the mail server from Sendmail to Postfix (useful only if you have both installed)?
alternatives --config mta
Using the chcon command - you can change the context of a file to work with Apache.
You have the flexibility to resize and add new volumes on the fly. With basic partitions - any time that you want to make a change - you need to destroy the partition and create it again.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.

6. What are SELinux Booleans?
SELinux Booleans provide restrictions to different aspects of a service.
You have the flexibility to resize and add new volumes on the fly. With basic partitions - any time that you want to make a change - you need to destroy the partition and create it again.
chcon
amount of RAM

7. What command can be used to view the queue for at service jobs?
atq
amount of RAM
Network address translation (NAT) maintains a table that allows the use of multiple internal IP addresses to a multiple public IP address (called address translation). It can also be used for one-to-one or one-to-many relationships as well.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.

8. The firewall service is...
browseable option
enabled by default
Use the resize2fs command to grow a file system.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.

9. What command can you use to view system processes and their CPU usage?
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
getfacl
You add your action to the end of the /home/user01/.bashrc file.
Use the ps command to view processes and their CPU usage.

10. Which file contains all messages generated during installation that can be used for troubleshooting if the need arises?
Use the yum groupinstall command to install multiple packages in a single group at once.
amount of RAM
support for TCP Wrappers
The install.log.syslog file contains messages that are generated during the installation. If you run into trouble during the installation - this is a good place to start.

11. What is the default port that Squid runs on?
By default - Squid runs on port 3128.
The /etc/fstab file.
Using the chcon command - you can change the context of a file to work with Apache.
enabled by default

12. By default - what is the path to a user's home directory?

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13. What is the /etc/vsftpd/user_list file used for?
Enforcing during installation
The user_list file can be used to limit which users have access to the FTP server.
lvdisplay
The mount command lists all currently mounted file systems.

14. What is a virtual host?
SELinux Booleans provide restrictions to different aspects of a service.
Enforcing during installation
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
A virtual host is a way of hosting multiple sites using a single IP address.

15. Before you work with ACLs - what do you need to do to the file system?
SELinux provides enhanced granular security for the Linux operating system.
The rndc utility provides a method for managing the DNS server remotely and securely.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.

16. How would you go about creating a static route?
Use the route command with the add option to create a static route.
The ping command can be used to verify connectivity to another host.
This chapter described tdbsm and smbpasswd back-end authentication.
By default - the rndc utility listens on port 953.

17. What option at the GRUB boot menu can you use to append something to a kernel?
Use the yum groupinstall command to install multiple packages in a single group at once.
amount of RAM
This is actually a trick question because the answer could go either way. In this chapter - we discussed only software RAID setups - in which case the answer is no. If - however - you were using a hardware RAID 5 - the answer would be yes.
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.

18. What happens if a host changes its IP address and the keys don't match?

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19. What critical step must you take after updating the kernel to a newer version?
You must ensure that the /boot/grub/grub.conf file has the new entry for your newly updated kernel to be able to boot into it.
Use the top command to view CPU and memory usage.
You must open TCP ports 20 and 21 for the FTP server to function properly.
alternatives --config mta

20. What command (and options) can be used to create a user named George with the description "Jr Admin"?
The du and df commands are used to view available space on the system.
Use the resize2fs command to grow a file system.
useradd -c "Jr Admin" George
A gateway is used as an entry and exit point for a subnet on a network. To contact hosts outside your subnet - you need to pass through a gateway.

21. What command can you use to create a file system?
Typing the mail or mutt command allows you to read mail from the command line.
Use the setgid flag to create the appropriate permissions (chmod 2770).
mkfs.ext4
The smbstatus command shows you currently mounted Samba resources.

22. You must dictate the ____________ you want allocated to your virtual machine when you create it.
The /var/log/audit/audit.log file contains all policy violations.
amount of RAM
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
You add your action to the end of the /home/user01/.bashrc file.

23. What client-side command can you use to test your FTP server connection?
Yum repository config files (.repo files) are located in the /etc/yum.repos.d directory. You can also make direct entries into the main /etc/yum.conf file.
The lftp command can be used on a client to test FTP server connections.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
The du and df commands are used to view available space on the system.

24. What option can you change in the rsyslog config file to accept remote logs (acting as a centralized logging server)?
A swap is scratch space on your file system used as virtual memory. A swap can be created as a partition or a device file.
LUKS encryption
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514

25. How do you run a command with elevated privileges?
The three utilities are: route - ping - and nslookup.
rpcbind service
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
The two main config files are master.cf and main.cf.

26. What are the two config files for Postfix called?
A user's home directory is created under the /home directory.
The two main config files are master.cf and main.cf.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
Using the chcon command - you can change the context of a file to work with Apache.

27. The portmap service was replaced by the ______________ in Red Hat Enterprise Linux 6.
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
chkconfig—list
rpcbind service
SSH is used for secure remote management of Linux systems.

28. What does the following firewall rule accomplish: iptables -I INPUT 5 -p tcp -m tcp --dport 80 -j ACCEPT?
When the system enters into runlevel 2 - the rsyslog service has a priority of 12 when starting. Anything with a lower number (or the same number and lower first letter) starts before the rsyslog service.
load balancing and redundancy benefits
Use the yum groupinstall command to install multiple packages in a single group at once.
The firewall rule is inserted into the fifth line of the iptables rules and opens up TCP port 80 (for the HTTP service) on the firewall to allow incoming connections.

29. A service needs to have _______________ to be able to use it.
support for TCP Wrappers
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
Using the chcon command - you can change the context of a file to work with Apache.

30. Red Hat Enterprise Linux 6 is the only version that officially supports _______
cat /proc/mdstat
LUKS encryption
VNC is used to control a remote desktop session.
You can use the authconfig-tui command or the authconfig command.

31. Through its main config file - SSH can be configured to...

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32. What is the benefit to using centralized authentication?

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33. What command can you use to check the config file of the DHCP server?
browseable option
service dhcpd configtest
Public/private key authentication provides an additional layer of security because you need the correct key instead of just knowing someone's password. Passwords combined with public/private keys take the security one additional step.
getfacl

34. If a package is built on an RHEL6 system and deployed to a custom RHEL5 repository - are RHEL5 systems able to use it?
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
The anonymous_enable=YES option in the main config file allows anonymous uploads.

35. How would you disable SELinux protection for NFS - allowing shares to be read/write?
You should never allow remote root access. Should your root account become compromised and you use the same password - someone could gain access to all your systems. You also don't want the most powerful user of your system (with no accountability) l
Use the resize2fs command to grow a file system.
By default - Squid runs on port 3128.
setsebool -P nfs_export_all_rw=1

36. What command do you use to report information on quota usage?
amount of RAM
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
SELinux Booleans provide restrictions to different aspects of a service.
repquota

37. A PXE server eases the automation process but isn't required for...
kickstart installations to work
The mount command lists all currently mounted file systems.
You can use the remove or erase options with yum to remove a package.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.

38. Does a DHCP server allow reserved IP addresses - If so - how?
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
If you shrink a volume group or logical volume - there is a chance you could lose data depending on how much you shrink the volume.
service sshd statuts
alternatives --config mta

39. What port does the DHCP server listen on by default?
The dig - host - and ping commands can be used to test DNS server functionality.
The DHCP server listens on port 67 by default.
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
The NFS service uses TCP port 2049 by default.

40. What command can be used to easily list all the options in the FTP main config file?
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
ifconfig
rpcbind service
alternatives --config mta

41. What are the three items that make up LVM?
Physical volumes - volume groups - and logical volumes.
The three utilities are: route - ping - and nslookup.
mkfs.ext4
The dig - host - and ping commands can be used to test DNS server functionality.

42. What command is used to create an RPM package?
you have access to the correct packages or repositories.
Use the top command to view CPU and memory usage.
A swap is scratch space on your file system used as virtual memory. A swap can be created as a partition or a device file.
rpmbuild

43. Samba servers can...
PAM is used as a modular way to leverage security. In this chapter - the main function we discussed was for managing password policies and complexity.
serve both files and printers to users
The service command is used to start - stop - and manage system services.
The SMTP service runs on TCP port 110.

44. How can you display all virtual guests after they're connected to a hypervisor?
The smbstatus command shows you currently mounted Samba resources.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
Using the chcon command - you can change the context of a file to work with Apache.
You can use the remove or erase options with yum to remove a package.

45. What command can you use to view mounted Samba shares?
The smbstatus command shows you currently mounted Samba resources.
A swap is scratch space on your file system used as virtual memory. A swap can be created as a partition or a device file.
kickstart installations to work
Use the top command to view CPU and memory usage.

46. The at command is used to ____________. The cron service handles reoccurring system jobs.
schedule one-time-only jobs
service named configtest
semanage boolean -l
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).

47. FTP is one of three protocols ______________. The other two protocols are NFS and HTTP.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
used for kickstart and/or network installs
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.

48. What is SSH used for?
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
The chmod command is used to change the permissions of files and directories. The chown command is used to change the ownership of files and directories.
repquota
SSH is used for secure remote management of Linux systems.

49. What command can you use to monitor and troubleshoot network connections?
The tcpdump command is used to monitor network connections on different interfaces.
The install.log.syslog file contains messages that are generated during the installation. If you run into trouble during the installation - this is a good place to start.
A user's home directory is created under the /home directory.
The virsh command is used to manage virtual guests.

50. If you want a specific action to take place when user01 logs in to the system - which file would you edit?
You add your action to the end of the /home/user01/.bashrc file.
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
rpmbuild