1z0-100: Oracle Linux 5 and 6 System Administration

Which statements is true concerning Oracle Linux configuration files for users and groups?

The /etc/passwd file contains hashed passwords for each user.
The /etc/shadow file contains hashed passwords for each user.
The GECOS field in /etc/passwd file may be empty.
The /etc/group file contains the group name and the hashed group password.

Correct answer: B

Explanation:

/etc/shadow file stores actual password in encrypted (one-way hashed) format for user's account with additional properties related to user password i.e. it stores secure user account information

Examine this extract from the /etc/ssh/sshd_config file:

passwordAuthentication no

What is the effect of this parameter settings on the use of openSSH commands on both the client and server?

Passwords are not required and no ssh-keygen is required either. Only passphrase are required.
Client users whose keys are not in the authorized_keys file on the server are unable to use passwords to authenticate themselves to the server.
The ssh daemon does not ask for a password before starting or stopping the sshd service.
Client users whose keys are not in the authorized_keys file on the client are unable to use passwords to authenticate themselves to the server.

Correct answer: B

Explanation:

If you set PasswordAuthentication to no, you will no longer be able to use a login and password to authenticate and must use a login and public key instead (if PubkeyAuthentication is set to yes).

This MDADM output:

Which two aspects can be determined from this output?

A device failed and has been removed from this RAID set.
It is no longer possible to write to this RAID set.
Read and write performance is no longer optimal on this RAID set.
This RAID set was built without a spare device.
Only Write performance is no longer optimal on this RAID set.

Correct answer: AD

Examine the command on its output:

[root@FAROUT ~] # modprobe –v nfs
Insmod /lib/modules/2.6.39-100.0.12.e16uek.x86_64/kernel/fs/nfs_common/nfs_acl.ko insmod /lob/modules/2.6.39-
100.0.12.e16uek.x86_64/kernel/net/sunrpc/auth_gss/auth_rpcgss.ko
Insmod /lib/modules/2.6.39-100.0.12.e16uek.x86_64/kernel/fs/fscache/fscache/ko
Insmod /lib/modules/2.6.39-100.0.12.e16uek.x86_64/kernel/fs/locked.ko
Insmod /lib/modules/2.6.39-100.0.12.e16uek.x86_64/kernel/fs/nfs/nfs.ko

Which two statements are true about the modprobe command?

It will load the nfs module if all the modules upon which it depends have been loaded.
It displays the dependency resolution for the nfs module and loads all the modules upon which nfs depends before loading the nfs module.
It verifies that the nfs module and all other modules that depend on the nfs module are installed.
It displays the dependency resolution that would occur if the nfs module were to be loaded using modprobe nfs.
It only loads the nfs module if all the modules upon which it depends have not been loaded yet.

Correct answer: AB

What is the main advantage of the Oracle Unbreakable Enterprise Kernel compared with the Red Hat compatible kernel?

It is more secure and, therefore, more difficult to hack.
It has a lower Mean Time Between Failures.
It provides higher availability for applications by reducing Mean Time to Recovery.
It scales better for more CPUS, memory, and Infiniband network connections.

Correct answer: D

Explanation:

The Unbreakable Enterprise Kernel, for those who want to leverage the latest features from mainline Linux and boost performance and scalability. The Red Hat Compatible Kernel, for those who prefer strict Red Hat kernel ABI (kABI) compatibility.

The Unbreakable Enterprise Kernel, for those who want to leverage the latest features from mainline Linux and boost performance and scalability.

The Red Hat Compatible Kernel, for those who prefer strict Red Hat kernel ABI (kABI) compatibility.

Examine this output:

# df –t nfs FilesystemSizeUsedAvailUse%Mounted on o16:export30G21G7.6G74%/mnt
# 1s -1 /mnt/nfs.sh -rwxr-mr-x. 1 root root 22 May 8 16:37 /mnt/nfs.sh
# file /mnt/nfs.sh /mnt/nfs.sh: Bourne-Again shell script text executables
# /mnt/nfs.sh bash: /mnt/nfs.sh: Permission denied

What is the reason for the error?

The file system was exported on host o16 using the ROOT_SQUASH option.
The /export filesystem was mounted with the NOEXEC option on host o16.
The filesystem mounted on /mnt was mounted with the NOEXEC option.
The filesystem was exported on host o16 by using the NO_ROOT_SQUASH option.

Correct answer: C

Which two software packages are prerequisites for enabling the configuration and use of a Network information Service (Nis) client?

nis-tools
slapi-nis
ypbind
nisserv
nisbind
yp-tools

Correct answer: CF

Explanation:

ypbind finds the server for NIS domains and maintains the NIS binding information. The client (normaly the NIS routines in the standard C library) could get the information over RPC from ypbind or read the binding files.

ypbind finds the server for NIS domains and maintains the NIS binding information.

The client (normaly the NIS routines in the standard C library) could get the information over RPC from ypbind or read the binding files.

You recently updated the strace package to the latest version as shown:

What is the outcome of running this command?

It downgrades the strace package to version 4.5.19-1.6.e16.
It downgrades strace package to version 4.5.19-1.11.e16_3.2.
It fails with an error because you cannot downgrade a package using the yum command.
It fails with an error because there are multiple versions available to which Yum can downgrade the strace package.
It will prompt you to select a version of the strace package that you want to downgrade.

Correct answer: A

Which statement is true concerning the /etc/sysconfig directory and its files and subdirectories?

The contents are always the same for a specific version of the Oracle Linux Kernel.
The file /etc/sysconfig/init is used by upstart to control the attributes of the tty devices that get started.
The directory /etc/sysconfig/network-scripts contains files that must not be modified while the network is up.
The files only contain default values for certain daemon processes.

Correct answer: B

Explanation:

The /etc/sysconfig/init file controls how the system appears and functions during the boot process. Note: The /etc/sysconfig directory contains files that control your system's configuration. The contents of this directory depend on the packages that you have installed on your system

The /etc/sysconfig/init file controls how the system appears and functions during the boot process.

Note: The /etc/sysconfig directory contains files that control your system's configuration. The contents of this directory depend on the packages that you have installed on your system

Examine the routing table: