Oracle Oracle Certifications 1Z0-460 Questions & Answers

• Question 41:

  View the following GRUB command or the output of fixing the GRUB boot problem:

  

  Based on the output, which statement is true?

  A. The GRUB command sequence restores GRUB from the first partition on the second hard disk.

  B. The GRUB command sequence does not restore GRUB.

  C. GRUB command sequence restores GRUB from the second partition on the first hard disk.

  D. The GRUB command sequence verifies the stage1 on the first partition on first hard disk.

  Correct Answer: C

  hd0,1 indicates the first hard drive and the second partition.

  Note:

  *

  grub - the grub shell

  Enter the GRand Unified Bootloader command shell.

  *

  In the following example we assume that the boot partition is located at /dev/hda5 and that GRUB must

  be installed on the first disk's MBR.

  grub> root (hd0,4) Filesystem type is ext2fs, partition type 0x83 grub> setup (hd0) Checking if "/boot/grub/stage1" exists... yes Checking if "/boot/grub/stage2" exists... yes Checking if "/boot/grub/e2fs_stage1_5" exists... yes Running "embed /boot/grub/e2fs_stage1_5 (hd0)"... 23 sectors are embedded.

  succeeded Running "install /boot/grub/stage1 (hd0) (hd0)1+23 p (hd0,4)/boot/grub/stage2 /boot/grub/menu.lst"... succeeded Done. grub> quit The first command includes the location of the boot partition, thus indicating where the boot loader files are located. The second command installs GRUB on the MBR. For this purpose, a file called stage1_5 is used to grant GRUB access to the file system on the boot partition.

• Question 42:

  What does the following btrfs command do?

  $ sudo btrfs subvolume snapshot src src-01

  A. Creates snapshots of the src src-01 subvolumes

  B. Creates a snapshot of the src-01 subvolumes in src

  C. Creates the src and src-01 subvolumes and takes a snapshot of these subvolumes

  D. Creates a snapshot of the src subvolumes in src-01

  Correct Answer: D

  *

  To create a snapshot use

  sudo btrfs subvolume snapshot /mnt/@ /mnt/@_snapshot

  this will create a snapshot of the @ subvolume named @_snapshot located also in the top of the btrfs tree.

  *

  btrfs subvolume snapshot [/]

  Create a writable snapshot of the subvolume with the name in the directory.

• Question 43:

  You have to collect information about your Oracle Linux 6 system, such as hardware configuration, installed software packages, configuration, and operational state send it to Oracle Support. Which tool will help you gather this information for sending it to Oracle Support?

  A. sosreport

  B. iostat

  C. kdump

  D. strace

  E. systemstat

  Correct Answer: A

  sosreport - Generate debugging information for this system

  sosreport generates a compressed tarball of debugging information for the system it is run on that can be sent to technical support reps that will give them a more complete view of the overall system status.

  Incorrect: Not B: The iostat command is used for monitoring system input/output device loading by observing the time the devices are active in relation to their average transfer rates. The iostat command generates reports that can be used to change system configuration to better balance the input/output load between physical disks.

  Not C: kdump.conf is a configuration file for the kdump kernel crash collection service.

  kdump.conf provides post-kexec instructions to the kdump kernel. It is stored in the initrd file managed by the kdump service. If you change this file and do not want to restart before it takes effect, restart the kdump service to rebuild to initrd. Not D: strace - trace system calls and signals

• Question 44:

  Which two statements are correct about the Oracle ASMLib library?

  A. Oracle ASMLib is an optional support library for the Automatic Storage Management (ASM) feature.

  B. To use ASMLib library, you have to recompile it first for the Unbreakable Enterprise Kernel.

  C. Oracle Automatic Storage management (ASM) requires Oracle ASMLib library to function completely.

  D. Oracle ASMLib kernel driver is included in the Unbreakable Kernel.

  Correct Answer: AD

  A (not C): ASMLib is an optional support library for the Automatic Storage Management feature of the

  Oracle Database.

  ASMLib allows an Oracle Database using ASM more efficient and capable access to the disk groups it is

  using.

  D (not B): The Oracle ASMLib kernel driver is now included in the Unbreakable Enterprise Kernel. No

  driver package needs to be installed when using this kernel.

• Question 45:

  The crond daemon checks each command to see whether it should be run in the current ___________.

  A. Second

  B. Minute

  C. Hour

  D. Day

  Correct Answer: B

  The cron utility then wakes up every minute, examining all stored crontabs, checking each command to see if it should be run in the current minute.

• Question 46:

  Your Oracle Linux system has two network interfaces eth0 and eth1. You have to change the netmask and the IP address of the eth1 network interface. Which configuration file would you edit to make these changes?

  A. /proc/net/ifcg-eth1

  B. /etc/sysconfig/network-scripts/eth1

  C. /etc/sysconfig/network/ifcg-eth1

  D. /etc/sysconfig/network-scripts/ifcfg-eth1

  Correct Answer: D

  The "/etc/sysconfig/network-scripts/ifcfg-eth0" file holds the network configuration for the "eth0" adapter. If you have multiple network adapters, you would expect additional configuration files (eth1, eth2 etc.).

  Note:

  * The "/etc/sysconfig/network" file holds top-level networking configuration, including the hostname and gateway settings.

• Question 47:

  You have to aggregate two network interfaces, eth0 and eth1, into a single logical interface such as bond0. Which option shows the four configuration files that need to be configured to set up this bonding?

  A. /etc/sysconfig/network-scripts/ifcfg-bond0 /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/idfg-eth1 /proc/bonding.conf

  B. /etc/sysconfig/network-scripts/ifcfg-bond0 /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/idfg-eth1 /etc/modeprobe.d/bonding.cfg

  C. /etc/sysconfig/network/ifcfg-bond0 /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth1 /etc/modprobe.d/bonding.conf

  D. /etc/sysconfig/network-scripts/ifcfg-bond0 /etc/sysconfig/network-scripts/eth0 /etc/sysconfig/network-scripts/eth1 /etc/bonding.conf

  Correct Answer: C

  *

  Step #1: Create a Bond0 Configuration File

  Red Hat Enterprise Linux (and its clone such as CentOS) stores network configuration in /etc/sysconfig/ network-scripts/ directory. First, you need to create a bond0 config file as follows: # vi /etc/sysconfig/network-scripts/ifcfg-bond0

  *

  Step #2: Modify eth0 and eth1 config files

  Open both configuration using a text editor such as vi/vim, and make sure file read as follows for eth0 interface # vi /etc/sysconfig/network-scripts/ifcfg-eth0

  *

  Step # 3: Load bond driver/module

  Make sure bonding module is loaded when the channel-bonding interface (bond0) is brought up. You need

  to modify kernel modules configuration file:

  For each configured channel bonding interface, there must be a corresponding entry in your new /etc/

  modprobe.d/bonding.conf file.

• Question 48:

  You want to allow multiple users the write access to files within the same directory, in addition, you want all the new files created in this directory to be of the required group instead of the primary ID of the user who creates the file. How do you accomplish this?

  A. Set the setgid bit on the directory.

  B. Change the group owner of the new files manually.

  C. Run a cron job to change the group owner.

  D. Change the primary group ID of every user to the required group.

  Correct Answer: A

  Linux: SETGID on directory

  SETGID stands for SET Group ID. We can use the command chmod to set the group ID bit for a directory.

  chmod g+s mydir

  or with numeric mode:

  chmod 2775 mydir

  After the change, the permission of the directory "mydir" becomes "drwxrwsr-x".

  drwxrwsr-x 3 zen zen 4096 2010-03-18 19:57 mydir

  But what is so special about setting the group ID for a directory? The trick is that when another user creates a file or directory under such a directory "mydir", the new file or directory will have its group set as the group of the owner of "mydir", instead of the group of the user who creates it.

  For example, if user2 belongs to the groups "user2" (main group) and "zen", and he creates a file "newfile" under the diretory "mydir", "newfile" will be owned by the group of "zen" instead of user2's main group ID "user2".

• Question 49:

  Examine the sar command below. Your Oracle Linux system has one CPU. What does the runq- sz column of this output convey about your system?

  

  A. CPU is bottleneck because the run queue size is greater than the number of CPUs on your system.

  B. The average of three processes are only using the CPU on your system and hence the CPU is not a bottleneck.

  C. CPU is not a bottleneck because the run queue size indicates the number of CPU bound processes on your system.

  D. CPU is a bottleneck because the run queue size indicates that adequate memory is not allocated.

  Correct Answer: A

  *

  Use the sar -q command to report the following information:

  The Average queue length while the queue is occupied.

  The percentage of time that the queue is occupied.

  *

  The following list describes the output from the -q option.

  runq-sz The number of kernel threads in memory that are waiting for a CPU to run. Typically, this value should be less than 2. Consistently higher values mean that the system might be CPU-bound.

  %runocc

  The percentage of time that the dispatch queues are occupied.

  swpq-sz

  Swap queue of processes for the sar command.

  %swpocc

  Swap queue of processes for the sar command.

• Question 50:

  You have executed the following commands as the root user:

  # find /home | cpio o H tar F root@HostA: /dev/nst0 - - rsh command = /usr/bin/ssh

  What is the purpose of issuing this command?

  A. To archive the contents of the /home directory in the tar format to a remote host system's tape drive device /dev/nst0

  B. To archive the contents of the /home directory in the cpio format to a remote host system's tape device /dev/nst0

  C. To archive the contents of the /home directory in the cpio and tar formats to a remote system's tape drive device /dev/nst0

  D. To extract the contents of the /home directory from the tape drive device /dev/nst0

  Correct Answer: A

  Note:

  *

  The cpio command is one of standard Unix backup utilities. It stands for "copy in/out." It is much less well known and more rarely used Unix utility in comparison with tar.

  *

  The cpio command is one of standard Unix backup utilities. It stands for "copy in/out." It is much less well known and more rarely used Unix utility in comparison with tar.

  * -H format. Here tar