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 query information from the kernel about RAID arrays?
Kickstart supports both basic and advanced partitioning (RAID/LVM).
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
cat /proc/mdstat
support TCP Wrappers

2. What two commands are special for dealing with user login events?
The htpasswd command can be used to password-protect a web page.
setsebool -P nfs_export_all_rw=1
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
The lastlog and faillog commands are used to view user login-related events?

3. 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.
rpmbuild
defining a %pre section although it is rarely used
createrepo

4. Runlevel 0 ___________. Runlevel 6 reboots the system.
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 virsh command is used to manage virtual guests.
amount of RAM
halts the system

5. What is the superblock used for?
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.
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.

6. What command can you use to view system processes and their CPU usage?
Use the ps command to view processes and their CPU usage.
service sshd statuts
The yum and rpm commands are used for package management.
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

7. What command displays your current interfaces and IP address?
ifconfig
Physical volumes - volume groups - and logical volumes.
support for TCP Wrappers
The vsftpd package is used to install an FTP server.

8. What is the /etc/vsftpd/user_list file used for?
useradd -c "Jr Admin" George
SELinux Booleans provide restrictions to different aspects of a service.
The user_list file can be used to limit which users have access to the FTP server.
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.

9. What is the name of the package that allows you to install VNC?
entering rescue mode and repairing the problem.
SSH is used for secure remote management of Linux systems.
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
support TCP Wrappers

10. To create a RAID or LVM partition using kickstart
Kickstart supports both basic and advanced partitioning (RAID/LVM).
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.
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.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.

11. If you want a specific action to take place when user01 logs in to the system - which file would you edit?
By default - Squid runs on port 3128.
semanage boolean -l
You add your action to the end of the /home/user01/.bashrc file.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.

12. How would you disable SELinux protection for NFS - allowing shares to be read/write?
setsebool -P nfs_export_all_rw=1
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
createrepo
Use the route command with the add option to create a static route.

13. Which version of SSH should you use?
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.
A virtual host is a way of hosting multiple sites using a single IP address.
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.
Version 2 is the latest and most secure version of SSH.

14. The portmap service was replaced by the ______________ in Red Hat Enterprise Linux 6.
rpcbind service
The user_list file can be used to limit which users have access to the FTP server.
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.
chkconfig xinetd --list

15. What two commands are used for package management?
The yum and rpm commands are used for package management.
The user_list file can be used to limit which users have access to the FTP server.
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.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.

16. What port does the SMTP service run on?
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
defining a %pre section although it is rarely used
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 SMTP service runs on TCP port 110.

17. What is the benefit to using centralized authentication?

18. How can you check the currently mounted file systems?
The mount command lists all currently mounted file systems.
chkconfig sshd off
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.
Network installations can be performed using the HTTP - FTP - and NFS protocols.

19. What does it mean if you ping a host and you receive the response Destination Unreachable?
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 file that stores usernames and their encrypted passwords is erased and replaced with a new file.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
The yum and rpm commands are used for package management.

20. What is the default port that Squid runs on?
By default - Squid runs on port 3128.
The TFTP server uses UDP port 69.
The smbpasswd command is used to create Samba users.
Using the chcon command - you can change the context of a file to work with Apache.

21. What is the benefit of using public/private key authentication?

22. What is a virtual host?
A virtual host is a way of hosting multiple sites using a single IP address.
support TCP Wrappers
halts the system
run on any port you'd like (provided that port is available)

23. What are the two config files for Postfix called?
The two main config files are master.cf and main.cf.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
By default - Squid runs on port 3128.
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.

24. How can you display all virtual guests after they're connected to a hypervisor?
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.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
via the command line
VNC is used to control a remote desktop session.

25. What is the difference between an A record and a PTR record?
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
browseable option
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
Use the top command to view CPU and memory usage.

26. The firewall service is...
user's home directory in the /etc/skel directory
enabled by default
For Apache to run a secure site - the mod_ssl package is required to be installed.
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.

27. What is the /var/lib/nfs/etab file used for?
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.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.

28. What command can you use to validate the syntax of the Apache config file?
The /var/log/audit/audit.log file contains all policy violations.
alternatives --config mta
service httpd configtest
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.

29. Is it possible to share files among groups - What permissions would you set on the directory to accomplish file sharing if possible?
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
Use the setgid flag to create the appropriate permissions (chmod 2770).
The SMTP service runs on TCP port 110.
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.

30. What command can you use to get information about logical volumes?
lvdisplay
SSH is used for secure remote management of Linux systems.
Use the route command with the add option to create a static route.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.

31. What directory is used to represent the virtual file system created by the kernel?
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
Use the ps command to view processes and their CPU usage.

32. What two ports should be opened on the firewall for the FTP server to function properly?
Use the top command to view CPU and memory usage.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
You must open TCP ports 20 and 21 for the FTP server to function properly.

33. The ____________ is available for each share.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
support for TCP Wrappers
browseable option
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.

34. What port does the rndc utility listen on by default?
The -t nfs option is used with the mount command to mount NFS resources.
semanage boolean -l
By default - the rndc utility listens on port 953.
The ping command can be used to verify connectivity to another host.

35. A slave DNS server provides...
The yum and rpm commands are used for package management.
generates errors under Red Hat Enterprise Linux 6
load balancing and redundancy benefits
mkfs.ext4

36. How would you go about creating a static route?
Use the route command with the add option to create a static route.
Use the yum groupinstall command to install multiple packages in a single group at once.
createrepo
Enforcing during installation

37. What command can you use to manage system services?
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.
setsebool -P nfs_export_all_rw=1
The service command is used to start - stop - and manage system services.
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.

38. Which remote management service is installed by default?Can you name the port that it uses?
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 tcpdump command is used to monitor network connections on different interfaces.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
defining a %pre section although it is rarely used

39. What option is used with both the fdisk and parted commands to display the current partition tables?
Enforcing during installation
DNS uses port 53.
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.
The print option is used with both the fdisk and parted commands to display the current partition tables.

40. How can virtual hosts be used?
The dig - host - and ping commands can be used to test DNS server functionality.
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.
You can use the remove or erase options with yum to remove a package.
Use the top command to view CPU and memory usage.

41. What command disables the SSH service from running when the system boots?
chkconfig sshd off
support TCP Wrappers
The smbpasswd command is used to create Samba users.
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

42. What is the /etc/hosts file used for?

43. Samba servers can...
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
semanage boolean -l
serve both files and printers to users

44. What does the testparm command do?
Enforcing during installation
VNC is used to control a remote desktop session.
The virsh command is used to manage virtual guests.
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.

45. What protocols are used with Dovecot?
Use the yum groupinstall command to install multiple packages in a single group at once.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
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.

46. 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.
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.
alternatives --config mta
Network installations can be performed using the HTTP - FTP - and NFS protocols.

47. 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...

48. What does ifconfig 172.168.1.100 netmask 255.255.255.0 eth1 do?
The /etc/fstab file.
The smbstatus command shows you currently mounted Samba resources.
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.
service named configtest

49. What command is used to change the mail server from Sendmail to Postfix (useful only if you have both installed)?
alternatives --config mta
user's home directory in the /etc/skel directory
Kickstart supports both basic and advanced partitioning (RAID/LVM).
createrepo

50. What command and option do you use to view the description of Boolean values?
semanage boolean -l
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
The -t nfs option is used with the mount command to mount NFS resources.
Using the chcon command - you can change the context of a file to work with Apache.