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 benefit of using public/private key authentication?

2. What command can you use to query Boolean values?
getsebool
rpmbuild
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
ifconfig

3. The exportfs command is used to...
generates errors under Red Hat Enterprise Linux 6
The TFTP server uses UDP port 69.
export one or all resources
The yum and rpm commands are used for package management.

4. Most boot issues can be resolved by...
The mount command lists all currently mounted file systems.
support TCP Wrappers
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
entering rescue mode and repairing the problem.

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

6. Which remote management service is installed by default?Can you name the port that it uses?
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
Typing the mail or mutt command allows you to read mail from the command line.
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 VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.

7. To grow a file system
Use the yum groupinstall command to install multiple packages in a single group at once.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
The user_list file can be used to limit which users have access to the FTP server.
Use the resize2fs command to grow a file system.

8. How do you run a command with elevated privileges?
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.
chkconfig sshd off
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
Enforcing during installation

9. What does S12rsyslog in the /etc/rc.d/rc2.d directory mean?
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 TFTP server uses UDP port 69.
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.
This command reboots virtual guest Client04.

10. How can you display all virtual guests after they're connected to a hypervisor?
Typing the mail or mutt command allows you to read mail from the command line.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
enabled by default
The lastlog and faillog commands are used to view user login-related events?

11. Is it possible to share files among groups - What permissions would you set on the directory to accomplish file sharing if possible?
chkconfig xinetd --list
SSH is used for secure remote management of Linux systems.
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
Use the setgid flag to create the appropriate permissions (chmod 2770).

12. It is possible to run scripts before a kickstart installation. This is done by...
chkconfig xinetd --list
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
The four types of DNS servers are master - slave - caching-only - and forwarding.
defining a %pre section although it is rarely used

13. There are four types of DNS servers. Name them.
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.
browseable option
The four types of DNS servers are master - slave - caching-only - and forwarding.
run on any port you'd like (provided that port is available)

14. The at command is used to ____________. The cron service handles reoccurring system jobs.
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
A virtual host is a way of hosting multiple sites using a single IP address.
schedule one-time-only jobs
The rdnc-confgen command generates an rndc.conf file for the rndc utility.

15. Can you name three utilities that can be used for network or DNS client troubleshooting?
rpcbind service
The NFS service uses TCP port 2049 by default.
The three utilities are: route - ping - and nslookup.
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.

16. What three protocols can you use to perform network installations?
Network installations can be performed using the HTTP - FTP - and NFS protocols.
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.
chkconfig—list
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.

17. What does it mean if you ping a host and you receive the response Destination Unreachable?
This command reboots virtual guest Client04.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
The nfsstat command can be used to view NFS statistics.
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.

18. What are the side effects of shrinking a volume group or logical volume?
You can use the authconfig-tui command or the authconfig command.
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.
By default - Squid runs on port 3128.
This command reboots virtual guest Client04.

19. What is the point of using SELinux?
via the command line
chcon
SELinux provides enhanced granular security for the Linux operating system.
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.

20. How can virtual hosts be used?
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
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.
browseable option
The /etc/fstab file.

21. What happens if a host changes its IP address and the keys don't match?

22. What file needs to be edited so that the system will mount a file system at boot time?
chkconfig—list
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
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 /etc/fstab file.

23. What two ports should be opened on the firewall for the FTP server to function properly?
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
createrepo
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
You must open TCP ports 20 and 21 for the FTP server to function properly.

24. What are the two config files for Postfix called?
The two main config files are master.cf and main.cf.
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.
Use the route command with the add option to create a static route.
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.

25. What command is used to show all services being controlled by the xinetd daemon?
run on any port you'd like (provided that port is available)
chkconfig xinetd --list
The lastlog and faillog commands are used to view user login-related events?
service sshd statuts

26. What option is used to allow anonymous uploads to the FTP server?
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
service dhcpd configtest
The anonymous_enable=YES option in the main config file allows anonymous uploads.
schedule one-time-only jobs

27. What is the /etc/vsftpd/user_list file used for?
The user_list file can be used to limit which users have access to the FTP server.
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.
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
Use the ps command to view processes and their CPU usage.

28. What is the format of the /etc/shadow file?
The three utilities are: route - ping - and nslookup.
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
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 DHCP server listens on port 67 by default.

29. What is the main config file for the DHCP service?
Use the ps command to view processes and their CPU usage.
ifconfig
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.

30. Which log file is used to keep track of policy violations?
The /var/log/audit/audit.log file contains all policy violations.
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 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.

31. What two commands are special for dealing with user login events?
repquota
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
run on any port you'd like (provided that port is available)
The lastlog and faillog commands are used to view user login-related events?

32. What command can you use to change the context of files?
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
chcon
schedule one-time-only jobs
alternatives --config mta

33. What file is used to maintain custom parameters for the kernel during system boot?
You must open TCP ports 20 and 21 for the FTP server to function properly.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
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.

34. What does the testparm command do?
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 entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.

35. What option would you use to query an installed package using the rpm command?
useradd -c "Jr Admin" George
enabled 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.
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.

36. What protocols are used with Dovecot?
getfacl
rpmbuild
lvdisplay
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.

37. If you want a specific action to take place when user01 logs in to the system - which file would you edit?
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
You add your action to the end of the /home/user01/.bashrc file.
The vsftpd package is used to install an FTP server.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.

38. What happens to jobs that are scheduled to run while the system is off?
used for kickstart and/or network installs
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
user's home directory in the /etc/skel directory
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.

39. What command can you use to view mounted Samba shares?
You add your action to the end of the /home/user01/.bashrc file.
service httpd configtest
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 smbstatus command shows you currently mounted Samba resources.

40. Which version of SSH should you use?
Version 2 is the latest and most secure version of SSH.
SELinux provides enhanced granular security for the Linux operating system.
chkconfig xinetd --list
choose which mode you'd like it to operate in

41. How would you install a group of packages all at a single time?
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
service sshd statuts
Use the yum groupinstall command to install multiple packages in a single group at once.
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.

42. What command can you use to create your own repositories?
export one or all resources
createrepo
used for kickstart and/or network installs
By default - Squid runs on port 3128.

43. What is SSH used for?
SSH is used for secure remote management of Linux systems.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
semanage boolean -l
The mount command lists all currently mounted file systems.

44. A service needs to have _______________ to be able to use it.
Enforcing during installation
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
support for TCP Wrappers

45. What command can you use to query information from the kernel about RAID arrays?
For Apache to run a secure site - the mod_ssl package is required to be installed.
browseable option
cat /proc/mdstat
The -t nfs option is used with the mount command to mount NFS resources.

46. 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 DHCP server listens on port 67 by default.
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.
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.

47. What is the name of the package that allows you to install VNC?
The nfsstat command can be used to view NFS statistics.
Physical volumes - volume groups - and logical volumes.
The smbstatus command shows you currently mounted Samba resources.
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.

48. Runlevel 0 ___________. Runlevel 6 reboots the system.
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
rpmbuild
Sendmail
halts the system

49. What port must be opened on the firewall for DNS?
DNS uses port 53.
The user_list file can be used to limit which users have access to the FTP server.
The tcpdump command is used to monitor network connections on different interfaces.
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.

50. Can you put your /boot partition on a RAID 5 array?
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
have the same effect
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.