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. The at command is used to ____________. The cron service handles reoccurring system jobs.
serve both files and printers to users
used for kickstart and/or network installs
schedule one-time-only jobs
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

2. What port does the Apache web server run on - What about HTTPS?
service httpd configtest
Apache uses port 80 for HTTP and port 443 for HTTPS.
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 /etc/fstab file.

3. What is the default port that Squid runs on?
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 SMTP service runs on TCP port 110.
you have access to the correct packages or repositories.
By default - Squid runs on port 3128.

4. What benefit does a web proxy provide to your network?
Use the resize2fs command to grow a file system.
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.
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.
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.

5. The portmap service was replaced by the ______________ in Red Hat Enterprise Linux 6.
Enforcing during installation
rpcbind service
Use the resize2fs command to grow a file system.
generates errors under Red Hat Enterprise Linux 6

6. What port does NFS use by default?
atq
The NFS service uses TCP port 2049 by default.
DNS uses port 53.
rpmbuild

7. What command can you use to view NFS statistics?
By defining a %post section - you can run scripts after a kickstart installation is complete.
The nfsstat command can be used to view NFS statistics.
The mount command lists all currently mounted file systems.
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.

8. What is the /var/lib/nfs/etab file used for?
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
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.

9. You must dictate the ____________ you want allocated to your virtual machine when you create it.
chkconfig—list
amount of RAM
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).

10. What command can you use to view system processes and their CPU usage?
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
Use the ps command to view processes and their CPU usage.
By default - Squid runs on port 3128.
DNS uses port 53.

11. What is a virtual host?
getsebool -a | grep http
The nfsstat command can be used to view NFS statistics.
A virtual host is a way of hosting multiple sites using a single IP address.
atq

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

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13. What command-line program can you use to check your mail?
Typing the mail or mutt command allows you to read mail from the command line.
VNC is used to control a remote desktop session.
The lftp command can be used on a client to test FTP server connections.
Network installations can be performed using the HTTP - FTP - and NFS protocols.

14. It is possible to run scripts before a kickstart installation. This is done by...
By defining a %post section - you can run scripts after a kickstart installation is complete.
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.
service sshd statuts
defining a %pre section although it is rarely used

15. FTP is one of three protocols ______________. The other two protocols are NFS and HTTP.
The rpm command can operate in install - query - or verify modes.
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
used for kickstart and/or network installs

16. The old SysInit scripts have been replaced in Red Hat Enterprise Linux 6 for what new boot utility?
You add your action to the end of the /home/user01/.bashrc file.
run on any port you'd like (provided that port is available)
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.

17. What is the superblock used for?
defining a %pre section although it is rarely used
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
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
serve both files and printers to users

18. What does ifconfig 172.168.1.100 netmask 255.255.255.0 eth1 do?
The nfsstat command can be used to view NFS statistics.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
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.
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George

19. What option needs to be used with the mount command to mount an NFS resource?
The -t nfs option is used with the mount command to mount NFS resources.
A virtual host is a way of hosting multiple sites using a single IP address.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
browseable option

20. The default SMTP service has been changed from _________ to Postfix in Red Hat Enterprise Linux 6.
The smbpasswd command is used to create Samba users.
Sendmail
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
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.

21. If you want a specific action to take place when user01 logs in to the system - which file would you edit?
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 add your action to the end of the /home/user01/.bashrc file.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
The smbpasswd command is used to create Samba users.

22. What command disables the SSH service from running when the system boots?
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.
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
chkconfig sshd off
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.

23. What command can you use to create your own repositories?
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
rpmbuild
SELinux provides enhanced granular security for the Linux operating system.
createrepo

24. A slave DNS server provides...
Apache uses port 80 for HTTP and port 443 for HTTPS.
alternatives --config mta
load balancing and redundancy benefits
The user_list file can be used to limit which users have access to the FTP server.

25. The ______________ for Red Hat Enterprise Linux 5 or 6 includes the use of LVM.
Enforcing during installation
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
The smbstatus command shows you currently mounted Samba resources.

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

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27. What command can you use to change the context of files?
rpmbuild
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.
chcon
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.

28. What is the biggest benefit to using LVM over basic partitions?
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
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 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.
support TCP Wrappers

29. What command would you use to create a group - to add the user George to the group?
have the same effect
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
The /var/lib/nfs/etab file is used to keep track of currently exported resources.

30. What is the xinetd service used for?
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
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.
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
useradd -c "Jr Admin" George

31. What is PAM used for?
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.
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.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
The anonymous_enable=YES option in the main config file allows anonymous uploads.

32. What is NAT - How is it used?
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
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.
VNC is used to control a remote desktop session.
The tcpdump command is used to monitor network connections on different interfaces.

33. What command do you use to change the permissions on a file or directory - To change ownership?
serve both files and printers to users
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
halts the system
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.

34. What are the three different types of RAID described in this chapter?
The service command is used to start - stop - and manage system services.
enabled by default
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
chkconfig xinetd --list

35. 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.
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 /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.

36. What port on the firewall needs to be open for the TFTP server to work?
The user_list file can be used to limit which users have access to the FTP server.
The mount command lists all currently mounted file systems.
The TFTP server uses UDP port 69.
getsebool

37. What command can you use to manage system services?
The service command is used to start - stop - and manage system services.
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.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.

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

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39. 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.
cat /proc/mdstat
kickstart installations to work
Typing the mail or mutt command allows you to read mail from the command line.

40. What client-side command can you use to test your FTP server connection?
kickstart installations to work
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
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 lftp command can be used on a client to test FTP server connections.

41. What command can you use to test the config files before starting the DNS service?
The /var/log/audit/audit.log file contains all policy violations.
You can use the remove or erase options with yum to remove a package.
service named configtest
The lftp command can be used on a client to test FTP server connections.

42. Is it possible to share files among groups - What permissions would you set on the directory to accomplish file sharing if possible?
rpmbuild
via the command line
Use the setgid flag to create the appropriate permissions (chmod 2770).
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.

43. How can you verify the status of the SSH service after the system has booted?
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
service sshd statuts
halts the system

44. What command is used to show all services being controlled by the xinetd daemon?
chkconfig xinetd --list
SELinux provides enhanced granular security for the Linux operating system.
The user_list file can be used to limit which users have access to the FTP server.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.

45. What does the partprobe command do?
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 partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.

46. Where are Yum repository config files located?
service httpd configtest
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
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.
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.

47. What command can be used to easily list all the options in the FTP main config file?
generates errors under Red Hat Enterprise Linux 6
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
Version 2 is the latest and most secure version of SSH.

48. Before you work with quotas - what do you need to do to the file system?
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
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.
Network installations can be performed using the HTTP - FTP - and NFS protocols.
choose which mode you'd like it to operate in

49. What command and options can you use to update the time?
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
The virsh command is used to manage virtual guests.
browseable option
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.

50. What is the virsh command used for?
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
chkconfig—list
The virsh command is used to manage virtual guests.
The -t nfs option is used with the mount command to mount NFS resources.