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 is the superblock used for?
rpmbuild
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
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 anonymous_enable=YES option in the main config file allows anonymous uploads.

2. What is PAM used for?
DNS uses port 53.
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 default - Squid runs on port 3128.
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.

3. Before you work with ACLs - what do you need to do to the file system?
Kickstart supports both basic and advanced partitioning (RAID/LVM).
browseable option
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.

4. What command is used to show all services being controlled by the xinetd daemon?
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.
A virtual host is a way of hosting multiple sites using a single IP address.
repquota
chkconfig xinetd --list

5. How would you disable SELinux protection for NFS - allowing shares to be read/write?
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.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
setsebool -P nfs_export_all_rw=1
rpcbind service

6. What port does the SMTP service run on?
The du and df commands are used to view available space on the system.
The SMTP service runs on TCP port 110.
The lastlog and faillog commands are used to view user login-related events?
LUKS encryption

7. What port does the DHCP server listen on by default?
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
createrepo
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
The DHCP server listens on port 67 by default.

8. What command can you use to create a new SSL certificate?
SELinux provides enhanced granular security for the Linux operating system.
This command reboots virtual guest Client04.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
The -t nfs option is used with the mount command to mount NFS resources.

9. What is the name of the package used to install an FTP?
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
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.
schedule one-time-only jobs
The vsftpd package is used to install an FTP server.

10. What are the two types of back-end authentication mechanisms discussed in this chapter?
This chapter described tdbsm and smbpasswd back-end authentication.
VNC is used to control a remote desktop session.
atq
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.

11. What command can you use to query Boolean values?
getsebool
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
Enforcing during installation

12. If a package is built on an RHEL6 system and deployed to a custom RHEL5 repository - are RHEL5 systems able to use it?
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
The -t nfs option is used with the mount command to mount NFS resources.
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
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.

13. How would you go about creating a static route?
chkconfig—list
Use the route command with the add option to create a static route.
service httpd configtest
alternatives --config mta

14. What is the /etc/vsftpd/user_list file used for?
The anonymous_enable=YES option in the main config file allows anonymous uploads.
chkconfig xinetd --list
The user_list file can be used to limit which users have access to the FTP server.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.

15. Which file shows you all the client IP addresses?
kickstart installations to work
support for TCP Wrappers
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
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

16. What is the biggest benefit to using LVM over basic partitions?
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 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 file that stores usernames and their encrypted passwords is erased and replaced with a new file.
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.

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

18. Which file contains all messages generated during installation that can be used for troubleshooting if the need arises?
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
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.
Use the top command to view CPU and memory usage.
mkfs.ext4

19. What file needs to be edited so that the system will mount a file system at boot time?
Version 2 is the latest and most secure version of SSH.
The /etc/fstab file.
The tcpdump command is used to monitor network connections on different interfaces.
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.

20. What is a gateway used for on a network?
Apache uses port 80 for HTTP and port 443 for HTTPS.
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 smbstatus command shows you currently mounted Samba resources.
service sshd statuts

21. Samba servers can...
serve both files and printers to users
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
The mount command lists all currently mounted file systems.
Use the setgid flag to create the appropriate permissions (chmod 2770).

22. 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 anonymous_enable=YES option in the main config file allows anonymous uploads.
The DHCP server listens on port 67 by default.
Use the top command to view CPU and memory usage.

23. Which log file is used to keep track of policy violations?
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
The /var/log/audit/audit.log file contains all policy violations.
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 /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.

24. What option would you use to query an installed package using the rpm command?
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 user's home directory is created under the /home directory.
The NFS service uses TCP port 2049 by default.
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.

25. The at command is used to ____________. The cron service handles reoccurring system jobs.
schedule one-time-only jobs
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
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.
SSH is used for secure remote management of Linux systems.

26. How can you verify the status of the SSH service after the system has booted?
service sshd statuts
via the command line
Version 2 is the latest and most secure version of SSH.
By default - Squid runs on port 3128.

27. How would you install a group of packages all at a single time?
Use the yum groupinstall command to install multiple packages in a single group at once.
getfacl
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
By defining a %post section - you can run scripts after a kickstart installation is complete.

28. Place all files you want added to a _______________ during creation.

29. 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.
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
entering rescue mode and repairing the problem.
useradd -c "Jr Admin" George

30. What does it mean if you ping a host and you receive the response Destination Unreachable?
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
rpcbind service
rpmbuild
amount of RAM

31. What is the main config file for the DHCP service?
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 NFS service uses TCP port 2049 by default.
This command reboots virtual guest Client04.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.

32. What command-line program can you use to check your mail?
The vsftpd package is used to install an FTP server.
support for TCP Wrappers
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.
Typing the mail or mutt command allows you to read mail from the command line.

33. What is VNC?
A user's home directory is created under the /home directory.
createrepo
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.
VNC is used to control a remote desktop session.

34. What command do you use to change the permissions on a file or directory - To change ownership?
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.
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.
You must open TCP ports 20 and 21 for the FTP server to function properly.
cat /proc/mdstat

35. Can you name the two commands that can be used to view the free space on the system?
used for kickstart and/or network installs
By default - Squid runs on port 3128.
You can use the remove or erase options with yum to remove a package.
The du and df commands are used to view available space on the system.

36. What are the three different types of RAID described in this chapter?
Enforcing during installation
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
export one or all resources
semanage boolean -l

37. What does the following firewall rule accomplish: iptables -I INPUT 5 -p tcp -m tcp --dport 80 -j ACCEPT?
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
serve both files and printers to users
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.
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.

38. What is the difference between an A record and a PTR record?
cat /proc/mdstat
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.

39. What are the two config files for Postfix called?
The print option is used with both the fdisk and parted commands to display the current partition tables.
The two main config files are master.cf and main.cf.
The SMTP service runs on TCP port 110.
rpmbuild

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

41. What are the three items that make up LVM?
Physical volumes - volume groups - and logical volumes.
getfacl
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
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.

42. Most boot issues can be resolved by...
user's home directory in the /etc/skel directory
entering rescue mode and repairing the problem.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
generates errors under Red Hat Enterprise Linux 6

43. What three commands can you use to help verify that the DNS server is functioning properly?
browseable option
halts the system
Enforcing during installation
The dig - host - and ping commands can be used to test DNS server functionality.

44. What command and options can you use to update the time?
semanage boolean -l
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
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.
The /var/lib/nfs/etab file is used to keep track of currently exported resources.

45. What are the five required directories when building RPMS?
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
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 can you use to create a file system?
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
mkfs.ext4
Use the route command with the add option to create a static route.
enabled by default

47. What is the benefit to using centralized authentication?

48. What is SSH used for?
enabled by default
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
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.
SSH is used for secure remote management of Linux systems.

49. What command can you use to test the config files before starting the DNS service?
The rpm command can operate in install - query - or verify modes.
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.
service named configtest
SSH is used for secure remote management of Linux systems.

50. What port does NFS use by default?
user's home directory in the /etc/skel directory
atq
The NFS service uses TCP port 2049 by default.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.