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 three commands can you use to help verify that the DNS server is functioning properly?
The du and df commands are used to view available space on the system.
you have access to the correct packages or repositories.
The dig - host - and ping commands can be used to test DNS server functionality.
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.

2. What is a gateway used for on a network?
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.
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.
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
Sendmail

3. What is the /var/lib/nfs/etab file used for?
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
rpmbuild
Use the top command to view CPU and memory usage.

4. What is a virtual host?
used for kickstart and/or network installs
The /etc/fstab file.
A virtual host is a way of hosting multiple sites using a single IP address.
The NFS service uses TCP port 2049 by default.

5. What are the three different types of RAID described in this chapter?
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
via the command line
service sshd statuts
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.

6. What three protocols can you use to perform network installations?
browseable option
service dhcpd configtest
Network installations can be performed using the HTTP - FTP - and NFS protocols.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.

7. What is the top command used for?
Use the top command to view CPU and memory usage.
A user's home directory is created under the /home directory.
Enforcing during installation
You must open TCP ports 20 and 21 for the FTP server to function properly.

8. A PXE server eases the automation process but isn't required for...
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
This command reboots virtual guest Client04.
kickstart installations to work
service httpd configtest

9. Before you work with ACLs - what do you need to do to the file system?
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.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.

10. What port does the rndc utility listen on by default?
service sshd statuts
defining a %pre section although it is rarely used
By default - the rndc utility listens on port 953.
LUKS encryption

11. What are the two config files for Postfix called?
The DHCP server listens on port 67 by default.
The two main config files are master.cf and main.cf.
This chapter described tdbsm and smbpasswd back-end authentication.
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.

12. What option would you use to query an installed package using the rpm command?
The print option is used with both the fdisk and parted commands to display the current partition tables.
The mount command lists all currently mounted file systems.
repquota
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.

13. What does S12rsyslog in the /etc/rc.d/rc2.d directory mean?
rpcbind service
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.
LUKS encryption
The vsftpd package is used to install an FTP server.

14. What command can be used to easily list all the options in the FTP main config file?
rpcbind service
Use the top command to view CPU and memory usage.
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.

15. What command can you use to change the context of files?
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
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.
You must open TCP ports 20 and 21 for the FTP server to function properly.
chcon

16. What does it mean if you ping a host and you receive the response Destination Unreachable?
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
getsebool -a | grep http
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.

17. What file needs to be edited so that the system will mount a file system at boot time?
amount of RAM
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
The /etc/fstab file.
chkconfig xinetd --list

18. The exportfs command is used to...
SELinux Booleans provide restrictions to different aspects of a service.
choose which mode you'd like it to operate in
export one or all resources
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.

19. What is the format of the /etc/shadow file?
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
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.
Physical volumes - volume groups - and logical volumes.
user's home directory in the /etc/skel directory

20. What happens to jobs that are scheduled to run while the system is off?
service named configtest
You can use the remove or erase options with yum to remove a package.
getsebool
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.

21. What command is used to change the mail server from Sendmail to Postfix (useful only if you have both installed)?
This command reboots virtual guest Client04.
createrepo
you have access to the correct packages or repositories.
alternatives --config mta

22. What is VNC?
VNC is used to control a remote desktop session.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.

23. Which version of SSH should you use?
serve both files and printers to users
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
Version 2 is the latest and most secure version of SSH.
The -t nfs option is used with the mount command to mount NFS resources.

24. What is the name of the section used to run scripts after a kickstart installation?
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.
halts the system
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.
By defining a %post section - you can run scripts after a kickstart installation is complete.

25. GRUB has three stages. Can you name them?
Stage 1: During this stage - the primary bootloader is read into memory by the BIOS from the MBR. Stage 1.5: During this stage - the bootloader is read into memory by the stage 1 bootloader (only if necessary). Stage 2: During this stage - the bootlo
export one or all resources
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.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.

26. The package selection screen allows you to install any software you want during the installation process as long as...
getsebool -a | grep http
you have access to the correct packages or repositories.
semanage boolean -l
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.

27. What command displays your current interfaces and IP address?
You add your action to the end of the /home/user01/.bashrc file.
The smbstatus command shows you currently mounted Samba resources.
ifconfig
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.

28. In Red Hat Enterprise Linux 6 - the default for SELinux is _______________ (which can be changed after the installation completes). For Red Hat Enterprise Linux 5 - you were able to choose what mode you wanted SELinux to start in.
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
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.
Enforcing during installation
rpmbuild

29. What command and option can you use to enable a service to start on boot?
The smbpasswd command is used to create Samba users.
VNC is used to control a remote desktop session.
service dhcpd configtest
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.

30. Most boot issues can be resolved by...
Use the resize2fs command to grow a file system.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
semanage boolean -l
entering rescue mode and repairing the problem.

31. What is a swap? Is it created as a partition or device file?
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.
You add your action to the end of the /home/user01/.bashrc file.
The user_list file can be used to limit which users have access to the FTP server.
entering rescue mode and repairing the problem.

32. What two commands are used for package management?
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.
The yum and rpm commands are used for package management.
entering rescue mode and repairing the problem.
load balancing and redundancy benefits

33. What are the two types of back-end authentication mechanisms discussed in this chapter?
This chapter described tdbsm and smbpasswd back-end authentication.
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.
you have access to the correct packages or repositories.
The yum and rpm commands are used for package management.

34. What command would you use to create a group - to add the user George to the group?
mkfs.ext4
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
Version 2 is the latest and most secure version of SSH.

35. What command can you use to query Boolean values?
getsebool
service httpd configtest
getsebool -a | grep http
The rndc utility provides a method for managing the DNS server remotely and securely.

36. How can you display all virtual guests after they're connected to a hypervisor?
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
This chapter described tdbsm and smbpasswd back-end authentication.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
The three utilities are: route - ping - and nslookup.

37. What is the virsh command used for?
The virsh command is used to manage virtual guests.
lvdisplay
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 anonymous_enable=YES option in the main config file allows anonymous uploads.

38. What command do you use to report information on quota usage?
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
The NFS service uses TCP port 2049 by default.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
repquota

39. What command can you use to query information from the kernel about RAID arrays?
By defining a %post section - you can run scripts after a kickstart installation is complete.
cat /proc/mdstat
Version 2 is the latest and most secure version of SSH.
halts the system

40. What two commands are special for dealing with user login events?
Use the route command with the add option to create a static route.
Sendmail
Kickstart supports both basic and advanced partitioning (RAID/LVM).
The lastlog and faillog commands are used to view user login-related events?

41. What is the name of the package that allows you to install VNC?
Use the ps command to view processes and their CPU usage.
generates errors under Red Hat Enterprise Linux 6
schedule one-time-only jobs
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.

42. Red Hat Enterprise Linux 6 is the only version that officially supports _______
semanage boolean -l
LUKS encryption
The smbpasswd command is used to create Samba users.
The /etc/fstab file.

43. What port on the firewall needs to be open for the TFTP server to work?
The SSH service is almost always installed by default in Red Hat. It uses TCP port 22 - and this port is open on the default firewall rules.
The TFTP server uses UDP port 69.
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.
chcon

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

45. Can you name the two commands that can be used to view the free space on the system?
The mount command lists all currently mounted file systems.
The du and df commands are used to view available space on the system.
chkconfig sshd off
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.

46. Can you name three utilities that can be used for network or DNS client troubleshooting?
The three utilities are: route - ping - and nslookup.
The rndc utility provides a method for managing the DNS server remotely and securely.
Use the route command with the add option to create a static route.
The /var/lib/nfs/etab file is used to keep track of currently exported resources.

47. Samba servers can...
serve both files and printers to users
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
Use the resize2fs command to grow a file system.
You must open TCP ports 20 and 21 for the FTP server to function properly.

48. Before you work with quotas - what do you need to do to the file system?
ifconfig
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
The mount command lists all currently mounted file systems.
Use the ps command to view processes and their CPU usage.

49. What command do you use to change the permissions on a file or directory - To change ownership?
Kickstart supports both basic and advanced partitioning (RAID/LVM).
The vsftpd package is used to install an FTP server.
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.
Enforcing during installation

50. It is possible to run scripts before a kickstart installation. This is done by...
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
defining a %pre section although it is rarely used
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.
serve both files and printers to users