Chapter 4-Linux

You've installed a third-party software package called MyApp. Where is the most likely place that this package is stored?

/opt/myapp

Which of the following directories is a virtual file system (VFS) that represents system information reported by the kernel?

/proc

What standard directory contains system logs?

/var/ or, more specifically, /var/log/

What are the three requirements for mounting a file system?

1.) A device (/dev/sdb1, for example) 2.) A directory (mount point) 3.) Root/superuser privileges.

What are the steps required to grow the file system /dev/data/datastore1 from its current 200 GB size to 400 GB?

1.) sudo umount /dev/data/datastore1 2.) sudo e2fsck-f /dev/data/datastore1 3.) sudo lvextend-L400G /dev/data/datastore1 4.) sudo resizefs /dev/data/datastore1 5.) sudo mount /dev/data/datastore1/data1

Which command can you use to create a new volume group, shared, with /dev/sdb1 and /dev/sdd1? And then how do you view your volume groups?

1.) vgcreate shared /dev/sdb1 /dev/sdd1 2.) vgdisplay

What final task do you need to complete in mounting a new file system to have that new file system mount at boot time?

Add its entry to the /etc/fstab file.

A junior administrator asks for your help with setting up a new Linux file system, /dev/sdb2. He retraces his steps with the fdisk, creating the partition and saving the setup.But now, he can't figure out why he can't use the file system-How can you help him?

After inspecting his work in fdisk, you tell him that he must build the file system with the mkfs command. You assist him by entering the following command: sudo mkfs.ext4 /dev/sdb2

You have a coworker who attempted to grow the file system on a Linux server. His problem is that the file system didn't extend despite entering the following command: sudo lvextend -L150G /dev/shared/graphics He remounted the file system onto /Graphics but the new space doesn't show up. What is the issue?

He forgot to issue the resizefs command to actually resize the file system. The lvextend command extends the partition size but does not affect the file system.

What does the -h switch in the command df -h do for you?

It presents disk free (df) data in a human-readable format (megabytes and gigabytes) for mounted file systems.

What type of file object is bin?

Link

How can you lists files in a hidden directory?

Similar to any other directory, either you cd into the hidden directory and issue the ls command or you explicitly name the hidden directory in your command, such as ls .ssh

One of the developers has told your manager that he needs the file system /code rebuilt using the XFS file system tape. Which utility can you use?

mkfs .xfs

How can you create a physical volume on /dev/sdd1?

pvcreate /dev/ssd1

How can you remove the physical volume on /dev/sdd1?

pvremove /dev/sde1

You know that for ext4 file systems, you use the resizefs utility to grow the file system, but which utility can you use to perform this same action on XFS file systems?

xfs_growfs

What is the generic format for the /etc/fstab file?

<Device or UUID> <Mount point> <File system tape> <Mount option> <Dump option> <fsck option>

If you issue the following command: sudo umount /share1 and you receive the error that the resource is busy, how do you fix the problem and unmount the file system?

A program or user, possibly you, is using the /share1 directory. You must close the program or otherwise ensure that it, yourself, or other users are not accessing the file system.

Examine the tree structure. What can you identify about your storage devices?

Answers may vary depending on the underlying hardware, but generally the system reserves sda1 and sda2 as boot file systems. The sda3 device is typically a logical volume group created by the system to house the root file system, the home file system, and swap space. Below that should be the two physical volumes that you created, and under each should be one or more logical volumes. Some of the logical volumes might extend across both physical volumes.

What command might you issue to track the I/o latency in real-time by sending 100 requests to the data backup volume?

Answers may vary, but one example is ioping -c 100 /dev/backup/databk.

Which command might you issue to track the storage usage of files on the data backup volume?

Answers may vary, but one example is: sudo du -h /backup/data.

How might you use these statistics to diagnose issues with a storage drive?

Answers may vary, but you compare the read and write statistics of the drive to see if they do or do not match the baseline of expected behavior. If they don't, the drive may be bottleneck and causing sluggish system behavior when users and applications read from read and write to storage.

You need to create a new volume for Human Resources. That group has purchased a new 1 TB drive for their volume. What is their volume? What is the first step in the process of creating the logical volume?

Create a partition using fdisk or a similar tool.

You and the other system administrators have a maintenance partition, /maint, that you only want mounted when required for administrative activities. How can you use the file system only when you need it?

Don't make an entry for /maint in the /etc/fstab file. Only mount the file system when you need it and then unmount it when finished.

The /bin directory typically contains which of the following files?

Essential command-line utilities.

Which directory or file system is a likely candidate on which to impose storage quotas on a shared Linux system?

The /home directory or file system because users tend to store everything without regard to space used. Quotas help prevent this kind of storage waste and file sprawl.

Explain the difference between /root and /

The /root directory is the root user's home directory and / is the root of the file system.

Why would an administrator use the ioping utility?

The ioping utility displays real-time I/O latency data to a specified volume.

If you cd to the root directory of the file system, name three directories that you'll see there.

The root of the file system is / and some possibilities are: /etc,/home,/opt,/mnt,/media,/boot,/dev,/proc,/tmp,/var,/lib,/bin,/sbin,/sys,/root,/and /user

The user has reached the soft limit for storage blocks. What does this mean as far as user's ability to write data to this file system?

The user will be able to continue to exceed this soft limit for default of seven days. If they go below the soft limit, the timer will reset. If they don't go below the soft limit within the grace period, or if they exceed the hard limit within the grace period, then they will be unable to write to the file system.

What does the iostat /dev/data/sda command do, and how can it be useful in troubleshooting?

This command generates read and write statistics for the /dev/sda block storage device. It can useful in troubleshooting because it can help you monitor storage usage statistics and identify poor performance associated with that device.

Why was no file or directory found, when you were just in a directory with this name>

This is because you referenced a relative path, which means Linux tried to open a directory called etc within /etc/ssh

As an administrator, you attempt to set quotas on /opt/finance for the finance group, but you receive the error that the mount point /opt/finance is not found or has no quota enabled. You verify that /opt/finance exists. You're trying to enable quotas, so it makes no sense that the error is that the file system has no quotas enabled. What is the problem?

You didn't edit /etc/fstab to add usrquota, grpquota options to the file system you wish to impose quotas on. You can also have to unmount/remount this file system after the change is made to /etc/fstab.

You created a new partition, /dev/sdb1, created the file system (XFS), and mounted the file system as /Files. You also created a few directories on /Files for various groups within your organization as shared file spaces. After a maintenance reboot a few days later, users are complaining that their directories and files and that you set up no longer exist. What is the problem?

You didn't make an entry for the new partition in /etc/fstab, therefore, the file system didn't mount on boot.

Why should you have to unmount a file system prior to performing an fsck on it?

You should unmount the file system to prevent damage such as file corruption.

If you cd into /opt/log/first/test/test1 and then cd ~ and press Enter, which directory is now your current working directory?

Your home directory. If your user name is bsmith, this is /home/bsmith. The cd ~ command returns you to your home directory regardless of where you are on the file system.

Which command can you use to create a new 400 GB logical volume, finance, from volume group vg_finance?

lvcreate --name finance --size 400G vg_finance

Which of the following Linux I/O schedulers is optimal in situations where a storage device platforms its own I/O sorting operations, or in non-mechanical devices like SSDs and USB flash drives?

noop

You're a new system administrator and your manager comes to your cubicle to give you a pop quiz on a few concepts. The first one she asks you is to show her how you would set up a new partition on the second storage drive on a Linux system. Which command can you enter to perform this operation?

sudo fdisk /dev/sdb

Another system administrator appears in your cubicle and asks you to display storage devices and their file systems on server05. Which command can you use to show him the info he needs?

sudo lsblk -f

How can you unmount the /finance file system?

sudo umount /finance