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 option at the GRUB boot menu can you use to append something to a kernel?
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
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 user_list file can be used to limit which users have access to the FTP server.

2. 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.
getsebool
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
The user_list file can be used to limit which users have access to the FTP server.

3. What command can you use to check the config file of the DHCP server?
The yum and rpm commands are used for package management.
You can use the remove or erase options with yum to remove a package.
chkconfig—list
service dhcpd configtest

4. What command can you use to create a password-protected page?
By default - Squid runs on port 3128.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
Enforcing during installation
The htpasswd command can be used to password-protect a web page.

5. If a package is built on an RHEL6 system and deployed to a custom RHEL5 repository - are RHEL5 systems able to use it?
You add your action to the end of the /home/user01/.bashrc file.
support TCP Wrappers
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.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.

6. FTP is one of three protocols ______________. The other two protocols are NFS and HTTP.
The print option is used with both the fdisk and parted commands to display the current partition tables.
used for kickstart and/or network installs
You can use the authconfig-tui command or the authconfig command.
The nfsstat command can be used to view NFS statistics.

7. What are the three items that make up LVM?
chkconfig sshd off
Physical volumes - volume groups - and logical volumes.
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.
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.

8. What command can you use to query Boolean values?
browseable option
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.
For Apache to run a secure site - the mod_ssl package is required to be installed.
getsebool

9. How can you verify the status of the SSH service after the system has booted?
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
service sshd statuts
choose which mode you'd like it to operate in
halts the system

10. What command would you use to create a group - to add the user George to the group?
The -t nfs option is used with the mount command to mount NFS resources.
The rndc utility provides a method for managing the DNS server remotely and securely.
chkconfig sshd off
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George

11. A service needs to have _______________ to be able to use it.
support TCP Wrappers
semanage boolean -l
enabled by default
support for TCP Wrappers

12. Runlevel 0 ___________. Runlevel 6 reboots the system.
The smbstatus command shows you currently mounted Samba resources.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
Physical volumes - volume groups - and logical volumes.
halts the system

13. What command is used to change the mail server from Sendmail to Postfix (useful only if you have both installed)?
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
run on any port you'd like (provided that port is available)
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
alternatives --config mta

14. How would you install a group of packages all at a single time?
cat /proc/mdstat
Use the yum groupinstall command to install multiple packages in a single group at once.
used for kickstart and/or network installs
The /etc/fstab file.

15. How can you display all virtual guests after they're connected to a hypervisor?
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
The /var/log/audit/audit.log file contains all policy violations.
The service command is used to start - stop - and manage system services.

16. What is the superblock used for?
You must open TCP ports 20 and 21 for the FTP server to function properly.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
chcon

17. The package selection screen allows you to install any software you want during the installation process as long as...
The rndc utility provides a method for managing the DNS server remotely and securely.
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 have access to the correct packages or repositories.
run on any port you'd like (provided that port is available)

18. Does a DHCP server allow reserved IP addresses - If so - how?
Physical volumes - volume groups - and logical volumes.
SSH is used for secure remote management of Linux systems.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
mkfs.ext4

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

20. What does the following firewall rule accomplish: iptables -I INPUT 5 -p tcp -m tcp --dport 80 -j ACCEPT?
alternatives --config mta
The du and df commands are used to view available space on the system.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
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 is the name of the section used to run scripts after a kickstart installation?
The /etc/fstab file.
By default - the rndc utility listens on port 953.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
By defining a %post section - you can run scripts after a kickstart installation is complete.

22. What command do you use to report information on quota usage?
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.
repquota
The vsftpd package is used to install an FTP server.
You add your action to the end of the /home/user01/.bashrc file.

23. What two ports should be opened on the firewall for the FTP server to function properly?
You must open TCP ports 20 and 21 for the FTP server to function properly.
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.
A soft limit acts like an alarm - signaling you when you are reaching your limit. If you don't specify a grace period - the soft limit is the max. A hard limit is required only when a grace period exists. It is the max limit you can hit before your g
service named configtest

24. What does S12rsyslog in the /etc/rc.d/rc2.d directory mean?
chcon
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 anonymous_enable=YES option in the main config file allows anonymous uploads.
load balancing and redundancy benefits

25. What is the name of the package that allows you to install VNC?
entering rescue mode and repairing the problem.
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
run on any port you'd like (provided that port is available)

26. What command is used to create an RPM package?
atq
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
used for kickstart and/or network installs
rpmbuild

27. What three commands can you use to help verify that the DNS server is functioning properly?
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 dig - host - and ping commands can be used to test DNS server functionality.
LUKS encryption
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.

28. What happens if you call the command from question 3 with the -c option after it has already been run?
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.
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
Use the top command to view CPU and memory usage.

29. What command can be used to easily list all the options in the FTP main config file?
halts the system
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
you have access to the correct packages or repositories.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.

30. What port does the rndc utility listen on by default?
You must open TCP ports 20 and 21 for the FTP server to function properly.
service dhcpd 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.
By default - the rndc utility listens on port 953.

31. What is NAT - How is it used?
The mount command lists all currently mounted file systems.
Using the chcon command - you can change the context of a file to work with Apache.
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 three utilities are: route - ping - and nslookup.

32. What is the main config file for the DHCP service?
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
The /var/log/audit/audit.log file contains all policy violations.
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
Network installations can be performed using the HTTP - FTP - and NFS protocols.

33. What port does the SMTP service run on?
The user_list file can be used to limit which users have access to the FTP server.
The SMTP service runs on TCP port 110.
semanage boolean -l
halts the system

34. How would you disable SELinux protection for NFS - allowing shares to be read/write?
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.
A user's home directory is created under the /home directory.
setsebool -P nfs_export_all_rw=1
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.

35. Editing the /etc/xinetd.d/tftp file and enabling the service are the same as running the chkconfig tftp on command. Both of these actions...
Sendmail
have the same effect
The -t nfs option is used with the mount command to mount NFS resources.
support TCP Wrappers

36. What does the rdnc-confgen command do?
serve both files and printers to users
chkconfig xinetd --list
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
The service command is used to start - stop - and manage system services.

37. What happens to jobs that are scheduled to run while the system is off?
service sshd statuts
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.
The print option is used with both the fdisk and parted commands to display the current partition tables.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.

38. Which file contains all messages generated during installation that can be used for troubleshooting if the need arises?
By default - Squid runs on port 3128.
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.
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. How can you list all services on the system to tell whether they will boot during startup?
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
kickstart installations to work
chkconfig—list
DNS uses port 53.

40. The old SysInit scripts have been replaced in Red Hat Enterprise Linux 6 for what new boot utility?
The mount command lists all currently mounted file systems.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
Version 2 is the latest and most secure version of SSH.
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.

41. Before you work with ACLs - what do you need to do to the file system?
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 smbpasswd command is used to create Samba users.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
browseable option

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

43. 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.
Enforcing during installation
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.
serve both files and printers to users
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.

44. What command-line program can you use to check your mail?
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.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
Typing the mail or mutt command allows you to read mail from the command line.
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.

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

46. The at command is used to ____________. The cron service handles reoccurring system jobs.
schedule one-time-only jobs
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
service dhcpd configtest
choose which mode you'd like it to operate in

47. What option is used with both the fdisk and parted commands to display the current partition tables?
The dig - host - and ping commands can be used to test DNS server functionality.
service httpd configtest
Typing the mail or mutt command allows you to read mail from the command line.
The print option is used with both the fdisk and parted commands to display the current partition tables.

48. What two commands are special for dealing with user login events?
The lastlog and faillog commands are used to view user login-related events?
The yum and rpm commands are used for package management.
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 /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.

49. What command can you use to query information from the kernel about RAID arrays?
cat /proc/mdstat
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
generates errors under Red Hat Enterprise Linux 6
VNC is used to control a remote desktop session.

50. A PXE server eases the automation process but isn't required for...
Sendmail
The du and df commands are used to view available space on the system.
kickstart installations to work
The /var/log/audit/audit.log file contains all policy violations.