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 view system processes and their CPU usage?
Use the ps command to view processes and their CPU usage.
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
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
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.

2. 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.
user's home directory in the /etc/skel directory
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
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.

3. Do you need to write changes to the disk when using the parted command? What about fdisk?
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 lftp command can be used on a client to test FTP server connections.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
By default - the rndc utility listens on port 953.

4. To create a RAID or LVM partition using kickstart
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.
kickstart installations to work
Kickstart supports both basic and advanced partitioning (RAID/LVM).
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.

5. GRUB has three stages. Can you name them?
Physical volumes - volume groups - and logical volumes.
For Apache to run a secure site - the mod_ssl package is required to be installed.
Kickstart supports both basic and advanced partitioning (RAID/LVM).
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

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

7. What commands can you use to add a client machine to an LDAP server?
You can use the authconfig-tui command or the authconfig command.
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.
You must open TCP ports 20 and 21 for the FTP server to function properly.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.

8. Does a DHCP server allow reserved IP addresses - If so - how?
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.
support for TCP Wrappers
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.

9. What does the rdnc-confgen command do?
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
By defining a %post section - you can run scripts after a kickstart installation is complete.
chkconfig xinetd --list
lvdisplay

10. What option at the GRUB boot menu can you use to append something to a kernel?
The DHCP server listens on port 67 by default.
getsebool
schedule one-time-only jobs
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.

11. What is PAM used for?
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.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
service dhcpd configtest
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.

12. Is it possible to share files among groups - What permissions would you set on the directory to accomplish file sharing if possible?
The smbpasswd command is used to create Samba users.
The NFS service uses TCP port 2049 by default.
The two main config files are master.cf and main.cf.
Use the setgid flag to create the appropriate permissions (chmod 2770).

13. What is the rndc utility used for?
via the command line
The rndc utility provides a method for managing the DNS server remotely and securely.
chcon
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

14. The package selection screen allows you to install any software you want during the installation process as long as...
The four types of DNS servers are master - slave - caching-only - and forwarding.
you have access to the correct packages or repositories.
You must open TCP ports 20 and 21 for the FTP server to function properly.
The tcpdump command is used to monitor network connections on different interfaces.

15. What command is used to change the mail server from Sendmail to Postfix (useful only if you have both installed)?
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.
alternatives --config mta
Use the ps command to view processes and their CPU usage.
Enforcing during installation

16. What are the two config files for Postfix called?
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.
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 two main config files are master.cf and main.cf.
A user's home directory is created under the /home directory.

17. The virt-install package allows you to manage virtual machines _____________. The virt-manager package allows you to manage virtual machines via a GUI interface.
via the command line
chkconfig—list
The NFS service uses TCP port 2049 by default.
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.

18. What does it mean if you ping a host and you receive the response Destination Unreachable?
used for kickstart and/or network installs
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
amount of RAM
Physical volumes - volume groups - and logical volumes.

19. The exportfs command is used to...
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
export one or all resources
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.

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

21. The firewall service is...
enabled by default
Use the setgid flag to create the appropriate permissions (chmod 2770).
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.

22. Are additional packages besides httpd required for a secure website - If so - what are they?
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
For Apache to run a secure site - the mod_ssl package is required to be installed.
Kickstart supports both basic and advanced partitioning (RAID/LVM).
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

23. What does S12rsyslog in the /etc/rc.d/rc2.d directory mean?
This chapter described tdbsm and smbpasswd back-end authentication.
The smbpasswd command is used to create Samba users.
service named configtest
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.

24. How can you list all services on the system to tell whether they will boot during startup?
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 partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
chkconfig—list
The lftp command can be used on a client to test FTP server connections.

25. What option would you use to query an installed package using the rpm command?
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
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.
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 gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.

26. How would you view all Boolean options for the HTTP service?
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 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
getsebool -a | grep http
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.

27. What port must be opened on the firewall for DNS?
DNS uses port 53.
The du and df commands are used to view available space on the system.
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.

28. The at command is used to ____________. The cron service handles reoccurring system jobs.
schedule one-time-only jobs
The /var/log/audit/audit.log file contains all policy violations.
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.
Version 2 is the latest and most secure version of SSH.

29. What command disables the SSH service from running when the system boots?
The NFS service uses TCP port 2049 by default.
chkconfig sshd off
LUKS encryption
The /etc/fstab file.

30. What two commands are special for dealing with user login events?
The nfsstat command can be used to view NFS statistics.
The mount command lists all currently mounted file systems.
The lastlog and faillog commands are used to view user login-related events?
entering rescue mode and repairing the problem.

31. What option can you change in the rsyslog config file to accept remote logs (acting as a centralized logging server)?
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.
support for TCP Wrappers
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
The -t nfs option is used with the mount command to mount NFS resources.

32. What does the testparm command do?
By defining a %post section - you can run scripts after a kickstart installation is complete.
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
repquota

33. What command can be used to view the queue for at service jobs?
LUKS encryption
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
you have access to the correct packages or repositories.
atq

34. What command can you use to change the context of files?
user's home directory in the /etc/skel directory
The two main config files are master.cf and main.cf.
Use the yum groupinstall command to install multiple packages in a single group at once.
chcon

35. What command can you use to create your own repositories?
createrepo
You must open TCP ports 20 and 21 for the FTP server to function properly.
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 mount command lists all currently mounted file systems.

36. The default SMTP service has been changed from _________ to Postfix in Red Hat Enterprise Linux 6.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
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.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
Sendmail

37. The old SysInit scripts have been replaced in Red Hat Enterprise Linux 6 for what new boot utility?
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
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 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.
mkfs.ext4

38. What command can you use to query information from the kernel about RAID arrays?
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.
cat /proc/mdstat
The lftp command can be used on a client to test FTP server connections.
setsebool -P nfs_export_all_rw=1

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

40. What two ports should be opened on the firewall for the FTP server to function properly?
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
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.
The nfsstat command can be used to view NFS statistics.
You must open TCP ports 20 and 21 for the FTP server to function properly.

41. How can you verify the status of the SSH service after the system has booted?
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
The /etc/fstab file.
enabled by default
service sshd statuts

42. It is possible to run scripts before a kickstart installation. This is done by...
semanage boolean -l
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
defining a %pre section although it is rarely used
chcon

43. 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...
createrepo
have the same effect
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
A user's home directory is created under the /home directory.

44. What is VNC?
run on any port you'd like (provided that port is available)
VNC is used to control a remote desktop session.
atq
cat /proc/mdstat

45. What three components are needed to fully automate a kickstart installation?
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 four types of DNS servers are master - slave - caching-only - and forwarding.
getfacl
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.

46. What command can you use to manage system services?
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
The service command is used to start - stop - and manage system services.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
rpmbuild

47. What is the benefit to using centralized authentication?

48. What command can be used to easily list all the options in the FTP main config file?
The nfsstat command can be used to view NFS statistics.
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.
Kickstart supports both basic and advanced partitioning (RAID/LVM).

49. What command can you use to create a file system?
The htpasswd command can be used to password-protect a web page.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
Use the ps command to view processes and their CPU usage.
mkfs.ext4

50. There are four types of DNS servers. Name them.
The four types of DNS servers are master - slave - caching-only - and forwarding.
serve both files and printers to users
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.