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. What command can you use to change the context of files?
chcon
You must open TCP ports 20 and 21 for the FTP server to function properly.
This command reboots virtual guest Client04.
run on any port you'd like (provided that port is available)

2. What command can you use to view system processes and their CPU usage?
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
Use the ps command to view processes and their CPU usage.
chkconfig—list
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.

3. What happens if you call the command from question 3 with the -c option after it has already been run?
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
Use the yum groupinstall command to install multiple packages in a single group at once.
halts the system
generates errors under Red Hat Enterprise Linux 6

4. What does ifconfig 172.168.1.100 netmask 255.255.255.0 eth1 do?
This command sets the eth1 interface to have a static IP address of 172.168.1.100 with a netmask of 255.255.255.0.
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.
chkconfig xinetd --list
support TCP Wrappers

5. Can you name the two commands that can be used to view the free space on the system?
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
useradd -c "Jr Admin" George
The du and df commands are used to view available space on the system.
service httpd configtest

6. What benefit does a web proxy provide to your network?
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
You should never use the -U option because it erases the prior kernel when updating. This leaves you with no fallback kernel should your system not boot properly.
This command sets the eth1 interface to have a static IP address of 172.168.1.100 with a netmask of 255.255.255.0.
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.

7. What is a virtual host?
The service command is used to start - stop - and manage system services.
A virtual host is a way of hosting multiple sites using a single IP address.
Use the top command to view CPU and memory usage.
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.

8. What command can you use to check the config file of the DHCP server?
DNS uses port 53.
The ping command can be used to verify connectivity to another host.
service dhcpd configtest
If you are a hosting company or want to run multiple websites/applications from a single IP address - you can use virtual hosts to accomplish this.

9. What is the name of the package used to install an FTP?
Use the top command to view CPU and memory usage.
mkfs.ext4
The vsftpd package is used to install an FTP server.
The dig - host - and ping commands can be used to test DNS server functionality.

10. For Red Hat Enterprise Linux 6 - SELinux comes set up in enforcing mode. When installing Red Hat Enterprise Linux 5 - you have the option to...

11. What are the three modes in which the rpm command can operate?
The -t nfs option is used with the mount command to mount NFS resources.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
The rpm command can operate in install - query - or verify modes.
have the same effect

12. Most boot issues can be resolved by...
entering rescue mode and repairing the problem.
By default - Squid runs on port 3128.
The virsh command is used to manage virtual guests.
repquota

13. A slave DNS server provides...
service dhcpd configtest
load balancing and redundancy benefits
The two main config files are master.cf and main.cf.
support TCP Wrappers

14. What is the superblock used for?
support TCP Wrappers
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
Use the route command with the add option to create a static route.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.

15. What option would you use to query an installed package using the rpm command?
mkfs.ext4
run on any port you'd like (provided that port is available)
You can use the -q option to query an installed package. Combining grep and the -qa options - you can search among all installed packages on the system.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.

16. What command can you use to create a file system?
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.
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 TFTP server uses UDP port 69.
mkfs.ext4

17. How would you go about creating a static route?
mkfs.ext4
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
The user_list file can be used to limit which users have access to the FTP server.
Use the route command with the add option to create a static route.

18. What client-side command can you use to test your FTP server connection?
Use the yum groupinstall command to install multiple packages in a single group at once.
chcon
service named configtest
The lftp command can be used on a client to test FTP server connections.

19. Do you need to write changes to the disk when using the parted command? What about fdisk?
This command sets the eth1 interface to have a static IP address of 172.168.1.100 with a netmask of 255.255.255.0.
When you exit the parted utility - all your changes are automatically written to disk. With the fdisk command - you need to manually write your changes to disk for them to take effect.
support for TCP Wrappers
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.

20. What command-line program can you use to check your mail?
Typing the mail or mutt command allows you to read mail from the command line.
LUKS encryption
service sshd statuts
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.

21. What command is used to show all services being controlled by the xinetd daemon?
chkconfig xinetd --list
getsebool -a | grep http
Sendmail
The nfsstat command can be used to view NFS statistics.

22. What port does the rndc utility listen on by default?
The ping command can be used to verify connectivity to another host.
By default - the rndc utility listens on port 953.
A user's home directory is created under the /home directory.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.

23. What is the last rule in the iptables file?

24. What command can you use to create a new SSL certificate?
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
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.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
generates errors under Red Hat Enterprise Linux 6

25. What port does NFS use by default?
The NFS service uses TCP port 2049 by default.
The lftp command can be used on a client to test FTP server connections.
For Apache to run a secure site - the mod_ssl package is required to be installed.
Use the route command with the add option to create a static route.

26. 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.
halts the system
Physical volumes - volume groups - and logical volumes.
You can use the authconfig-tui command or the authconfig command.

27. What is NAT - How is it used?
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.
The nfsstat command can be used to view NFS statistics.
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.
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.

28. What command would you use to create a group - to add the user George to the group?
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
Apache uses port 80 for HTTP and port 443 for HTTPS.
The smbstatus command shows you currently mounted Samba resources.
semanage boolean -l

29. What are the three items that make up LVM?
Physical volumes - volume groups - and logical volumes.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
The smbpasswd command is used to create Samba users.
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.

30. What are SELinux Booleans?
service httpd configtest
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
alternatives --config mta
SELinux Booleans provide restrictions to different aspects of a service.

31. The ______________ for Red Hat Enterprise Linux 5 or 6 includes the use of LVM.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
rpmbuild
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
Enforcing during installation

32. What command (and options) can be used to create a user named George with the description "Jr Admin"?
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
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.
useradd -c "Jr Admin" George
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.

33. What does the testparm command do?
SELinux provides enhanced granular security for the Linux operating system.
Use the yum groupinstall command to install multiple packages in a single group at once.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.

34. What command can you use to view mounted Samba shares?
service dhcpd configtest
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
The smbstatus command shows you currently mounted Samba resources.

35. What command do you use to report information on quota usage?
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.
repquota
used for kickstart and/or network installs
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.

36. What are the three different types of RAID described in this chapter?
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.
SSH is used for secure remote management of Linux systems.
rpmbuild
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).

37. What is the difference between an ext2 and ext3 file system?

38. Which file contains all messages generated during installation that can be used for troubleshooting if the need arises?
defining a %pre section although it is rarely used
rpmbuild
You can use the remove or erase options with yum to remove a package.
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.

39. What command can you use to manage system services?
The service command is used to start - stop - and manage system services.
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
Enforcing during installation

40. How would you install a group of packages all at a single time?
This command reboots virtual guest Client04.
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
Use the yum groupinstall command to install multiple packages in a single group at once.
mkfs.ext4

41. What critical step must you take after updating the kernel to a newer version?
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
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.
You add your action to the end of the /home/user01/.bashrc file.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.

42. What command can you use to validate the syntax of the Apache config file?
service httpd configtest
By default - Squid runs on port 3128.
The TFTP server uses UDP port 69.
amount of RAM

43. What directory is used to represent the virtual file system created by the kernel?
The lftp command can be used on a client to test FTP server connections.
Typing the mail or mutt command allows you to read mail from the command line.
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
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

44. What command can you use to create your own repositories?
createrepo
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
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.
cat /proc/mdstat

45. What does virsh reboot Client04 do?
Sendmail
The tcpdump command is used to monitor network connections on different interfaces.
This command reboots virtual guest Client04.
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.

46. What command is used to create an RPM package?
rpmbuild
A large warning message appears indicating that the key doesn't match the host you are connecting to. You have to remove the key/host pair from the known_hosts file to proceed.
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
If you are a hosting company or want to run multiple websites/applications from a single IP address - you can use virtual hosts to accomplish this.

47. What command is used to change the mail server from Sendmail to Postfix (useful only if you have both installed)?
mkfs.ext4
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.
choose which mode you'd like it to operate in
alternatives --config mta

48. How would you view all Boolean options for the HTTP service?
getsebool -a | grep http
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
The three utilities are: route - ping - and nslookup.
browseable option

49. What command displays your current interfaces and IP address?
ifconfig
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
Apache uses port 80 for HTTP and port 443 for HTTPS.
service sshd statuts

50. SSH does...
A large warning message appears indicating that the key doesn't match the host you are connecting to. You have to remove the key/host pair from the known_hosts file to proceed.
enabled by default
support TCP Wrappers
lvdisplay