In the following output from top, which processes contribute to the percentage of time that the CPU spends in the state of wa?Tasks: 193 total, 1 running, 190 sleeping, 2 stopped, 0 zombieCpu(s): 0.5%us, 0.3%sy, 0.0%ni, 98.2%id, 1.0%wa, 0.0%hi, 0.0%si, 0.0%st

Processes waiting for IO operations to complete.

Processes waiting for user interaction.

Processes that were already closed and are waiting to be launched again.

Processes that have not been scheduled yet because they haven't been fully loaded into RAM or are in swap.

Processes waiting for IO operations to complete.

When planning a web server which of the following choices will impact system sizing? (Choose THREE correct answers.)

How many concurrent users are expected.

What type of content will be served.

What scripting languages will the web server support.

How many concurrent users are expected.

Which hardware vendor has better Linux support.

What type of content will be served.

What scripting languages will the web server support.

Will the OS install be CD, DVD or network based.

What mechanism does collectd use to gather monitoring information on systems?

A master server connects to a collectd service on each machine to retrieve the information.

It collects its own information on each server and sends that to a master server.

It makes SNMP queries to the clients being monitored.

Which of the following is a side effect of extensive usage of swap space?

The overall system performance may degrade because of heavy hard disk use and memory reorganization.

The root filesystem may become full because swap space is always located on the system root partition.

The overall system performance may degrade because of heavy hard disk use and memory reorganization.

Since processes always exist completely in either RAM or swap, regular RAM may become unused if the kernel does not move processes back from the swap space to memory.

The memory may become fragmented and slow down the access to memory pages. However, this can be kept to a minimum by the regular use of memfrag -d.

Applications need to restart because their virtual memory addresses change to reflect memory relocation to the swap address area.

In this example output, which descriptions match the purpose of the free, buff and cache columns?(Choose THREE correct answers.)# vmstat 1 100procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----r b swpd free buff cache si so bi bo in cs us sy id wa0 0 0 282120 134108 5797012 0 0 0 2 0 0 0 0 100 00 0 0 282120 134108 5797012 0 0 0 0 1007 359 0 0 100 00 0 0 282120 134108 5797012 0 0 0 0 1117 577 0 0 100 00 0 0 282120 134108 5797012 0 0 0 0 1007 366 0 0 100 0

RAM available for filesystem buffers

In the following output, what is the 5 minute load average for the system?# uptime12:10:05 up 18 days, 19:00, 2 users, load average: 0.47, 24.71, 35.31

There is no 5 minute interval. It is some value between 0.47 and 24.71.

There is no 5 minute interval. It is some value between 24.71 and 35.31.

When is historical data of resource usage important? (Select THREE correct answers.)

Predicting when resources will need to be increased.

Troubleshooting a software problem.

Predicting when resources will need to be increased.

Identifying processes killed during out of memory occurrences.

Troubleshooting a software problem.

After installing a compiled kernel, it can not find any modules that are needed to be loaded. What make target was likely missed while installing the kernel?

make modules_install, modules_install

How can the kernel parameter for the maximum size of the shared memory segment (shmmax) be changed to 2GB (2147483648 Bytes) on a running system? (Choose TWO correct answers.)

sysctl kernel.shmmax=2147483648

echo 2147483648 > /proc/sys/kernel/shmmax

Edit /etc/shmmax and set the parameter to 2147483648.

sysctl kernel.shmmax=2147483648

echo 2147483648 > /proc/sys/kernel/shmmax

export kernel.shmmax=2147483648

Which directory contains the system-specific udev rule files? (Specify the absolute path including the directory name)

/etc/udev/rules.d,/etc/udev/rules.d/

What is a key difference between a zImage and bzImage kernel image?

zImage gets loaded completely into low memory. bzImage will load into high memory once low memory is full.

zImage is compressed using gzip, bzImage is compressed using bzip2.

zImage is for 2.6 series kernels, bzImage is for 3.x series kernels.

zImage is limited to 64k, bzImage has no such restriction.

zImage gets loaded completely into low memory. bzImage will load into high memory once low memory is full.

Which of the following command sequences can be used to extract files contained in a initramfs file(/boot/initramfs) which is used by the kernel at boot time?

cp /boot/initramfs /tmp/initramfs.gz; gunzip /tmp/initramfs.gz; mkdir /tmp/initramfs.dir ; cd/tmp/initramfs.dir ; cpio -i < /tmp/initramfs

cp /boot/initramfs /tmp/initramfs.gz; gzip -c /tmp/initramfs.gz; mkdir /tmp/initramfs.dir ; cd/tmp/initramfs.dir ; cpio -i < /tmp/initramfs

cp /boot/initramfs /tmp/initramfs.gz; gunzip /tmp/initramfs.gz; mkdir /tmp/initramfs.dir ; cd/tmp/initramfs.dir ; cpio -i < /tmp/initramfs

cp /boot/initramfs /tmp/initramfs.gz; gunzip /tmp/initramfs.gz; mount /tmp/initramfs /mnt/ -o loop -t initramfs

cp /boot/initramfs /tmp/initramfs.gz; gunzip /tmp/initramfs.gz; mkdir /tmp/initramfs.dir ; cd/tmp/initramfs.dir ; cpio -e /tmp/initramfs

cp /boot/initramfs /tmp/initramfs.gz; gunzip /tmp/initramfs.gz; mount /tmp/initramfs /mnt/ -o loop -t initrd

What information does the file modules.dep provide?

A list of all compiled modules and their dependencies.

A list of all modules, compiled or not, that are available to the kernel.

A list of modules trusted by the installed kernel.

A list of devices and their module name.

A list of all compiled modules and their dependencies.

A list of modules the kernel needs to run.

What is the purpose of the command udevadm monitor?

It listens to kernel events produced by a udev rule and print information to the console.

It monitors the /dev directory for new devices.

It monitors the udev process and prints performance statistics to the console.

It communicates with D-Bus to setup new devices.

How is the source code for the main Linux kernel modules distributed?

It is included with the Linux kernel source code.

The kernel modules are downloaded on demand as they are used during compilation.

The kernel modules have their own release cycle and can be maintained separately from the Linux kernel source.

It is provided as a separate download alongside the Linux kernel source code of the same version.

After changing the default runlevel in the SysV-init configuration file, the system boots in a different than intended runlevel. Where else could this different runlevel be defined?

In the boot loader configuration file

Why is the root file system mounted read-only during boot and remounted with write permission later on?

Because if problems with the root file system are detected during the boot, fsck can be run, without risk of damage.

Because this way crackers cannot collect information about root with boot sniffers.

To avoid writing to the disk, unless the root password is known.

To avoid other operating systems overwriting the Linux root partition.

Because the disk has its own write protection that cannot be changed by the operating system.

In case the file containing the Linux kernel is lost, what happens when the system is booting?

Without a kernel a system cannot boot and, depending on the bootloader, an error is displayed.

The system starts normally since the bootloader copies the kernel to the master boot record of the hard disk.

Instead of the kernel, the initramfs is loaded and instructed to mount the root filesystem and reinstall the kernel from the original package or from source.