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 is the format of the /etc/shadow file?
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.
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
rpcbind service


2. What is VNC?
The virsh command is used to manage virtual guests.
VNC is used to control a remote desktop session.
ifconfig
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.


3. The ____________ is available for each share.
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
browseable option
run on any port you'd like (provided that port is available)
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.


4. What command can you use to view NFS statistics?
SELinux Booleans provide restrictions to different aspects of a service.
cat /proc/mdstat
The nfsstat command can be used to view NFS statistics.
service httpd configtest


5. What option is used to allow anonymous uploads to the FTP server?
The du and df commands are used to view available space on the system.
The anonymous_enable=YES option in the main config file allows anonymous uploads.
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
Use the top command to view CPU and memory usage.


6. What port must be opened on the firewall for DNS?
You can use the authconfig-tui command or the authconfig command.
DNS uses port 53.
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
Enforcing during installation


7. What command disables the SSH service from running when the system boots?
For Apache to run a secure site - the mod_ssl package is required to be installed.
rpcbind service
chkconfig sshd off
have the same effect


8. A slave DNS server provides...
load balancing and redundancy benefits
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.
chkconfig sshd off
Use the resize2fs command to grow a file system.


9. It is possible to run scripts before a kickstart installation. This is done by...
This chapter described tdbsm and smbpasswd back-end authentication.
defining a %pre section although it is rarely used
Use the ps command to view processes and their CPU usage.
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.


10. What command is used to create an RPM package?
The rndc utility provides a method for managing the DNS server remotely and securely.
rpmbuild
generates errors under Red Hat Enterprise Linux 6
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.


11. There are four types of DNS servers. Name them.
Using the chcon command - you can change the context of a file to work with Apache.
entering rescue mode and repairing the problem.
The four types of DNS servers are master - slave - caching-only - and forwarding.
have the same effect


12. 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...
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
ifconfig
have the same effect
LUKS encryption


13. What is the superblock used for?
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.
useradd -c "Jr Admin" George
The tcpdump command is used to monitor network connections on different interfaces.


14. Before you work with quotas - 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 file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
The dig - host - and ping commands can be used to test DNS server functionality.
generates errors under Red Hat Enterprise Linux 6


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

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16. Can you name three utilities that can be used for network or DNS client troubleshooting?
The three utilities are: route - ping - and nslookup.
The mount command lists all currently mounted file systems.
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
The two main config files are master.cf and main.cf.


17. What are the five required directories when building RPMS?
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.
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
The two main config files are master.cf and main.cf.
The TFTP server uses UDP port 69.


18. What command can you use to create your own repositories?
Typing the mail or mutt command allows you to read mail from the command line.
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.
rpmbuild
createrepo


19. Samba servers can...
serve both files and printers to users
have the same effect
ifconfig
The rpm command can operate in install - query - or verify modes.


20. What command can you use to get information about logical volumes?
service httpd configtest
lvdisplay
The /var/log/audit/audit.log file contains all policy violations.
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.


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

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22. What command can you use to create a password-protected page?
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
The htpasswd command can be used to password-protect a web page.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
kickstart installations to work


23. 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.
Enforcing during installation
The nfsstat command can be used to view NFS statistics.
Typing the mail or mutt command allows you to read mail from the command line.


24. The package selection screen allows you to install any software you want during the installation process as long as...
lvdisplay
you have access to the correct packages or repositories.
DNS uses port 53.
The tcpdump command is used to monitor network connections on different interfaces.


25. What command would you use to create a group - to add the user George to the group?
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.
service named configtest
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
support TCP Wrappers


26. Explain the difference between soft and hard limits in quotas.

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

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28. What is the name of the section used to run scripts after a kickstart installation?
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.
By defining a %post section - you can run scripts after a kickstart installation is complete.
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
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.


29. What two commands are used for package management?
The anonymous_enable=YES option in the main config file allows anonymous uploads.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
The yum and rpm commands are used for package management.
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.


30. If you want a specific action to take place when user01 logs in to the system - which file would you edit?
The htpasswd command can be used to password-protect a web page.
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
The smbstatus command shows you currently mounted Samba resources.
You add your action to the end of the /home/user01/.bashrc file.


31. What are the two types of back-end authentication mechanisms discussed in this chapter?
The three utilities are: route - ping - and nslookup.
rpmbuild
This chapter described tdbsm and smbpasswd back-end authentication.
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.


32. What command and option do you use to view the description of Boolean values?
load balancing and redundancy benefits
The vsftpd package is used to install an FTP server.
semanage boolean -l
alternatives --config mta


33. To export directories as resources - what file needs to be edited?

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34. What directory is used to represent the virtual file system created by the kernel?
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
Enforcing during installation
getfacl
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.


35. To grow a file system
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
Use the resize2fs command to grow a file system.
SSH is used for secure remote management of Linux systems.
By default - Squid runs on port 3128.


36. What is a gateway used for on a network?
The lastlog and faillog commands are used to view user login-related events?
chcon
Enforcing during installation
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.


37. What command can you use to view mounted Samba shares?
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.
service dhcpd configtest
The smbstatus command shows you currently mounted Samba resources.
semanage boolean -l


38. What is the main config file for the DHCP 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.
By defining a %post section - you can run scripts after a kickstart installation is complete.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
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.


39. What protocols are used with Dovecot?
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
Typing the mail or mutt command allows you to read mail from the command line.
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
browseable option


40. The at command is used to ____________. The cron service handles reoccurring system jobs.
schedule one-time-only jobs
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
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.
mkfs.ext4


41. How would you install a group of packages all at a single time?
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.
Use the yum groupinstall command to install multiple packages in a single group at once.
A virtual host is a way of hosting multiple sites using a single IP address.
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.


42. What two commands are special for dealing with user login events?
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
serve both files and printers to users
The /etc/fstab file.
The lastlog and faillog commands are used to view user login-related events?


43. What is the difference between the update (-U) and install (-i) options when using rpm to update the kernel?
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 /var/lib/nfs/etab file is used to keep track of currently exported resources.
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.
Enforcing during installation


44. Which file contains all messages generated during installation that can be used for troubleshooting if the need arises?
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.
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
This chapter described tdbsm and smbpasswd back-end authentication.


45. What option is used with both the fdisk and parted commands to display the current partition tables?
lvdisplay
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
The print option is used with both the fdisk and parted commands to display the current partition tables.
The TFTP server uses UDP port 69.


46. If a package is built on an RHEL6 system and deployed to a custom RHEL5 repository - are RHEL5 systems able to use it?
SSH is used for secure remote management of Linux systems.
service sshd statuts
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
You add your action to the end of the /home/user01/.bashrc file.


47. How can you verify the status of the SSH service after the system has booted?
A virtual host is a way of hosting multiple sites using a single IP address.
service sshd statuts
useradd -c "Jr Admin" George
have the same effect


48. What file needs to be edited so that the system will mount a file system at boot time?
You can use the authconfig-tui command or the authconfig command.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
mkfs.ext4
The /etc/fstab file.


49. Can you put your /boot partition on a RAID 5 array?
Sendmail
getsebool -a | grep http
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.
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.


50. What command-line program can you use to check your mail?
The print option is used with both the fdisk and parted commands to display the current partition tables.
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 can use the authconfig-tui command or the authconfig command.
Typing the mail or mutt command allows you to read mail from the command line.