[[Category:OPS235]][[Category:OPS235 Labs]]{{Admon/caution|THIS IS AN OLD VERSION OF THE LAB|'''This is an archived version. Do not use this in your OPS235 course.'''}}= LAB PREPARATION =
=Logical Volume Management and Software Package Management=
==IntroductionPurpose / Objectives of Lab3==[[Image:software.png|thumb|right|300px|Installing software is an important task for computer system administrators. ]]
In this lab , you're are going to:identify potential problems such as not properly compressing VM image files when backing up VMs, or forgetting your root password. You will also learn to conserve hard disk space by learning how to compress and decompress files that are stored on your computer server. In addition, you will learn alternative methods of how to install applications (i.e. programs).
:* Learn how to add and remove software packages on your different Linux systems.:* Learn how to properly adjust your various Linux file systems by using and managing LVM both graphically (centos2) as well as command line (centos3).<u>Main Objectives</u>
== Required Materials *Learn to troubleshoot some common problems after installing VMs*Create and extract '''archive''' files (tar and tar.gz)*Install applications using various methods::*'''Download''', '''decompress''' and archive file from the Internet, then '''compile source code''' in order to install an application.:*Use '''yum''' utility to install software from '''local source programs''' (on DVD drive):*Use '''yum''' utility to install software from '''repositories''' (Bring online storage areas):*Learn how to All Labs'''add repositories''' (online software storage areas) to install less common applications.<ul><li value=="4">Demonstrate the use of Bash Shell scripts to automate routine tasks (generate a customized software report)</li></ul>
* CentOS 6.5 x86_64 Live DVD
* CentOS 6.5 x86_64 Installation DVD1
* SATA Hard Disk (in removable disk tray)
* USB Memory Stick
* Lab Logbook
==PrerequisitesMinimum Required Materials==
* Completion and Instructor {|cellpadding="Sign15" width="40%" |-offvalign="top" |width="10%" of Lab 2| [[Image: blank-cd.png|thumb|left|85px|<b>CentOS7</b><br>FULL DVD]] |width="10%" | [[OPS235 Lab 2 Image:harddrive.png|thumb|left|85px|<b>Removable Hard Disk Pack</b> (SATA)]] |width="10%" |[[Image:ubs- CentOS6key.png|thumb|left|85px|<b>USB key</b><br>(for backups)]] |width="10%" |[[Image:log-book.png|thumb|left|70px|<b>Lab3 Log Book</b>]] |} ==My Toolkit (CLI Reference)== {|width="100%" cellpadding="15"|- valign="top"|width="10%" |<u>Archiving / Compiling:</u>[http://man7.org/linux/man-pages/man1/tar.1.html tar]<br>[http://unixhelp.ed.ac.uk/CGI/man-cgi?gzip gzip, gunzip]<br>[http://man7.org/linux/man-pages/man1/make.1.html make]|width="10%" |<u>Software Manangement:</u>[http://www.rpm.org/max-rpm/rpm.8.html rpm]<br>[http://man7.org/linux/man-pages/man8/yum.8.html yum]|width="10%" |<u>Commands</u>[http://man7.org/linux/man-pages/man1/ls.1.html ls]<br>[http://man7.org/linux/man-pages/man1/more.1.html more]<br>[http://man7.org/linux/man-pages/man1/wget.1.html wget]<br>[http://man7.org/linux/man-pages/man1/chmod.1.html chmod]<br>[http://ss64.com/vi.html vi] |width="40%" |{{Admon/tip|Online Linux Command Review|The following tutorial will allow you to learn essential shell scripting skills:<ul><li>Shell Scripting Basics - Part 4 (The sed Utility):<br>'''/home/murray.saul/scripting-4'''</li></ul>|}}|}
==Linux Command Online Reference==
Each Link below displays online manpages for each command (via [http://linuxmanpages.com/ http://linuxmanpages.com]):
= INVESTIGATION 1: TROUBLESHOOTING AFTER VM INSTALLS & BACKUPS ={|width="10050%" align="right" cellpadding="510"|'''LVM Information Utilities:'''|'''LVM Management Utilities:'''|'''Additional Utilities:'''
|- valign="top"
|
*[http://linuxmanpages.com/man8/vgs.8.php vgs]*[httpImage://linuxmanpagesgrub1.com/man8/lvs.8.php lvs]*[http://linuxmanpages.com/man8/pvs.8.php pvs]*[http://linuxmanpages.com/man8/vgdisplay.8.php vgdisplay]*[http://linuxmanpages.com/man8/lvdisplay.8.php lvdisplay]*[http://linuxmanpages.com/man8/pvdisplay.8.php pvdisplay]png|thumb|right|*[http://www.centos.org/docs/5/html/Deployment_Guide-en-US/s1-system-config-lvm.html system-config-lvm] (Tutorial)*[http://linuxmanpages.com/man8/lvextend.8.php lvextend]*[http://linuxmanpages.com/man8/resize2fs.8.php resize2fs]*[http://linuxmanpages.com/man8/lvcreate.8.php lvcreate]*[http://linuxmanpages.com/man8/lvreduce.8.php lvreduce]*[http://linuxmanpages.com/man8/pvcreate.8.php pvcreate]*[http://linuxmanpages.com/man8/vgextend.8.php vgextend]600px|*[http://linuxmanpages.com/man8/mount.8.php mount]*[http://linuxmanpages.com/man8/umount.8.php umount]*[http://linuxmanpages.com/man8/yum.8.php yumPress '''e''' at Grub Boot Menu to edit]*[http://linuxmanpages.com/man8/rpm.8.php rpm]
|}
There are a few "classic problems" that students can encounter with their virtual machines and their host machine after performing lab2. Although all OPS235 students may not encounter these problems, it is good to be aware of what a potential problem may look like, and know how to solve that problem.
==Resources on the web==
Additional links to tutorials and HOWTOs:
'''Please read this page to get an overview of LVM:'''<br /><br />
:* [[Logical Volume Management]] ('''Note:''' It is recommended to return to this guide as a reference when performing the next several investigations)
:* [http://fedoranews.org/alex/tutorial/rpm/ Using the RPM Utility]
:* [http://www.centos.org/docs/5/html/yum/ Using the YUM Utility]
'''A few common problems are:'''
*I Can't boot into Graphical Mode on my '''c7host''' machine
*I Forgot My '''Regular User''' Password
*I Forgot My '''root''' Password
*I Can't Start My Virtual Machine
*I Can't start my Host machine
=Logical Volume Management (Introduction)=
== Check Current LVM Information Prior to Performing Investigations ==
'''LVM''' ('''Logical Volume Management''') is used to manage hard disk drives / partitions for Unix/Linux systems. LVM provides more flexibility than just working with hard disks / hard disk partitions. '''Volume Groups''' are areas used to define '''Physical Volumes''' (i.e. hard disks, disk partitions, or other forms Troubleshooting consists of storage devices). ''3 basic elements:'Logical Volumes''' are then used to relate directories (mount points) to a specific physical volume or for a "range" or "span" of physical volumes.
Therefore, LVM allows more flexibility and growth potential for Linux systems *'''Asking Questions''' (for example, having Logical volumes span multiple hard diskseg. what was done recently prior to problem?). CentOS uses LVM by default upon installation. Other Linux distributions may provide *'''Eliminating''' what the capacity problem '''IS NOT'''*'''Tenacity''' and '''patience''' (ability to install LVM, or later install and then use Logical Volume Management.focus on finding the cause of the problem)
'''Although the concept of LVM is simple, it takes practice and preparation (or "thinking ahead") in order to correctly use this valuable tool'''. It is important for students to gain an understanding of LVM, and how to manage their filesystems using LVM. It is recommended for students to read the following resource prior to this lab and/or return to the following resource while performing this lab: [[Logical Volume Management]]
At this point, having completed [[OPS235 Lab 2 - CentOS6|Lab 2]] you should have roughly the following disk storage setup:
If you cannot log graphically into your machine (first 3 common problems), there is a trick to boot your system into '''Note:single-user''' These results are output from mode. This mode does not provide networking, graphics, or logging in as other regular users, but can connect to a text-based interface as the '''vgsroot''', user. This method will only work if a GRUB (<u>'''pvsGr''', </u>and '''lvs<u>U</u>'''nified <u>'''B''' commands that provide volume group</u>oot-loader) password has not been set, physical volume and logical volume information for each of the virtual machines or that you created in lab2. Before proceeding, check these values with your own system to see if you are generally "on haven't forgotten the right track"GRUB password.)
* '''centos1'''
VG #PV #LV #SN Attr VSize VFree
vg_centos1 1 2 0 wz--n- 9.50g 0
PV VG Fmt Attr PSize PFree /dev/vda3 vg_centos1 lvm2 a'''Steps to Boot into "Single-- 9.50g 0User Mode":'''
LV VG Attr LSize Origin Snap{| width="50% " align="right" cellpadding="10"|- valign="top"|[[Image:grub2_1.png|thumb|right|600px|Add the boot option '''single''' and then press '''ctrl-x''' to boot into single user mode]]|}#Boot-up your '''centos1''' VM. '''when the Grub Boot menu appears''', press the letter <b><code><span style="color:#3366CC;font-size:1.2em;">e</span></code></b> (for "edit").#Using your arrow keys, scroll to next screen to Move Log Copy% '''linux''' Convertor '''linux-efi''' command and type the word <b><code><span style="color:#3366CC;font-size:1.2em;">single</span></code></b> as an argument after '''quiet''' (see diagram for reference) and then press <b><code><span style="color:#3366CC;font-size:1.2em;">ctrl-x</span></code></b> to boot. lv_root vg_centos1 #The system should boot into text-wibased mode. Enter your '''root''' password.#One thing to look at is partition space usage. Issue the command: <b><code><span style="color:#3366CC;font-ao 8size:1.03g 2em;">df -h</span></code></b> lv_swap vg_centos1 #If you notice 0% free space in the '''/''' partition, then there is a problem. This most likely is caused by not following steps to create a <u>compressed</u> copy of the VM image. If that is the case, locate the large image backup and remove it. Do NOT remove the image in ''/var/lib/libvirt/images'' directory!#You can use the '''passwd''' command to reset your '''regular user''' password (eg. <b><code><span style="color:#3366CC;font-wisize:1.2em;">passwd regularuserid</span></code></b>). You can press '''ctrl-ao c''' if you wish to abort (i.e. not change password).#To restart in graphical mode, simply enter the command <b><code><span style="color:#3366CC;font-size:1.47g 2em;">reboot</span></code></b>.
* :Unfortunately, this method does not work if you forgot your '''centos2root'''password (To reset your root password, refer to procedure below).
VG #PV #LV #SN Attr VSize VFree
vg_centos2 1 3 0 wz--n- 19.51g 7.77g
PV VG Fmt Attr PSize PFree /dev/vda2 vg_centos2 lvm2 a-- 19.51g 7.77g'''Steps to Reset Root's Password:'''
LV VG Attr LSize Pool Origin Data{| width="50% Move Log Cpy%Sync Convert" align="right" cellpadding="10" lv_home vg_centos2 -wi-ao-|-valign="top"|[[Image:grub2_3.png|thumb|right|600px|Add '''rw init=/sysroot/bin/sh''' as shown and then press '''ctrl-x''' to boot into single user no root password mode]]|}#The procedure to reset root's password is different than shown above. Press <b><code><span style="color:#3366CC;font- size:1.95g 2em;">e</span></code></b> at the Grub boot menu. lv_root vg_centos2 #Using your arrow keys, move to '''linux''' or '''linux-wiefi''' command and replace the argument '''ro''' with the argument <b><code><span style="color:#3366CC;font-aosize:1.2em;">rw init=/sysroot/bin/sh</span></code></b> (see diagram for reference) and then press <b><code><span style="color:#3366CC;font-size:1.2em;">ctrl-x</span></code></b> to boot.#The system should boot into text-based mode without prompting for root's password.#Issue the command: <b><code><span style="color:#3366CC;font- 7size:1.81g 2em;">chroot /sysroot</span></code></b><br><br> lv_swap vg_centos2 -wi-ao#Issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">passwd root</span></code></b> in order to change your root password (press '''ctrl-c''' if you wish to abort -i.e. not change password).#To restart in graphical mode, simply enter the command <b><code><span style="color:#3366CC;font- size:1.97g 2em;">reboot</span></code></b>.
* '''centos3 (Note: This VM has no GUI installed)'''
VG #PV #LV #SN Attr VSize VFree
vg_centos3 1 3 0 wz--n- 14.51g 4.54g
PV VG Fmt Attr PSize PFree /dev/vda3 vg_centos3 lvm2 a-- 14.51g 4.54g'''Catastrophic Boot Problems:'''
LV VG Attr LSize Origin Snap% Move Log Copy% Convert lv_home vg_centos3 -wi-ao---- 1:Not being able to start your '''c7host''' due to '''Kernel Panic''' or some sort of '''catastrophic disk failure''' is not as easy to fix. You might be able to boot from your '''Centos LIVE DVD, open a terminal and mount the partition''' via command line and look for possible problems (setup files like '''/etc/fstab''').00g lv_root vg_centos3 -wi-ao---- 8'''Lab5''' will discuss more about mounting and the /etc/fstab file.00g lv_swap vg_centos3 The "worst-wicase scenario" would be to purchase a new hard disk, '''perform lab1 completely, perform lab2 to install and set-ao---- 992.00m * up virtualization software''', then '''restore your VM image and xml file backups'''c6host (ieg.edecompressing images, issuing virsh define commands for . "removable hard disk" or "disk pack"xml files). That is why consistently '''performing backups of ALL of your VMS at the end of each lab is absolutely essential! You have been warned!'''
Does not use LVM. Confirm this using the same commands used above.= INVESTIGATION 2: ARCHIVING FILES =
{{Admon/note|VM Backups and Recovery|Most of these investigations will take place in your virtual machines. If you make ==Part 1: Creating a significant mistake, your virtual machine may not boot. Remember that you created backups of your virtual machines in Lab 2, and you can restore them if something goes wrong.<br /><br />'''Remember: if you did not create backups for all of your VMs, then you don't have any restoration points to fall-back to!'''|}}File Archive==
#Boot up your '''centos3''' VM.#Change your working directory to '''/usr/share/doc/sudo*'''#Use the tar (tape archiver) command to create an archive file named '''/tmp/archive1.tar'''#*<b><code><span style== Investigation 4"color: Extend the #3366CC;font-size of lv_root using command-line tools ==:1.2em;">tar cvf /tmp/archive1.tar .</span></code></b>
Perform this investigation in centos3{| width="40%" align="right" cellpadding="10"|- valign="top"|colspan="2"|{{Admon/important | Warning! | Don't miss the '''.''' at the end of the <code>tar</code> commands below! It specifies what should go into the archive: the contents of the current directory.}}
Let|}<ol> <li value="4">What do the options '''c''', '''v'''s say that you have run out of disk space on your computer (centos3), and '''f''' mean?</li> <li>Record the archive file size.</li> <li>Compress the file using '''gzip''': <ul> <li><b><code><span style="color:#3366CC;font-size:1.2em;">gzip /tmp/archive1.tar</span></code></b></li> </ul> </li> <li>Record the archive file size after compression.</li> <li>Make sure you need more space on the root filesystem, perhaps to host more webpages or 're still in '''/usr/share/doc/sudo*''' and then create a larger database or new softwarecompressed archive:<ul> <li><b><code><span style="color:#3366CC;font-size:1.2em;">tar cvzf /tmp/archive2. tgz .</span></code></b></li> </ul> </li> <li>What are your optionsdoes the''' z''' option do? Getting a replacement harddrive would probably require reinstallation </li> <li>Compare the sizes of the operating system '''/tmp/archive1.tar.gz''' and backup'''/tmp/restore of the dataarchive2.tgz'''.Why are they so close in size?</li></ol>
Because we're using LVM though - we can avoid that. We can add a new harddrive (which will serve as a physical volume) to the volume group, and extend the root logical volume to make use of ''Answer the new available spacePart 1 observations / questions in your lab log book.'''
===Part 2: Restoring Files From an Archive===#Remain in your '''centos3'Perform '' VM.#Create the following operations directory '''/tmp/extract1'''#Change to increase the '''/tmp/extract1''' directory.#Move the file '''archive1.tar.gz''' to your current directory.#Unzip the first archive you created:#*<b><code><span style="color:#3366CC;font-size:1.2em;">gunzip archive1.tar.gz</span></code></b>#Extract the files from the first archive:#*<b><code><span style="color:#3366CC;font-size:1.2em;">tar xvf archive1.tar</span></code></b>#Are all the files there? #Compare '''/tmp/extract1/README''' and '''/usr/share/doc/sudo*/README'''. Are they exactly the same? Why?#Create the directory '''/tmp/extract2'''#Move the file '''archive2.tgz''' to the '''/tmp/extract2''' directory.#Extract the files from the second archive:#*<b><code><span style="color:#3366CC;font-size:1.2em;">tar xvzf /tmp/extract2/archive2.tgz</span></code></b>#Note that this time a separate <b><code><span style="color:#3366CC;font-size of lv_root in centos3:1.2em;">gunzip</span></code></b> command was not needed. Why?#Repeat the previous command, leaving out the option '''z'''. Does it work? Why?#Compare the '''README'''file in this directory with the original file. Are they exactly the same?
<u>'''<font>Steps:<Answer Part 2 observations /font>questions in your lab log book.'''</u>
<ol>
<li>Run the following commands and make note of the output:</li>
<code>ls /dev/vd*
pvs
vgs
lvs
df -h</code>
<li>Open the centos3 virtual machine console</li>
<li>Go to the hardware details view</li>
<li>Click "Add Hardware" and add a new storage device of 2GBs, make sure it's a VirtIO disk.</li>
<li>Go back to the console view</li>
<li>Run the same ls command (performed in step 1), what's changed?</li>
<li>Now we'll make the new device as a physical volume, add it to the volume group, and extend lv_root:</li>
<code>pvcreate /dev/vdb
vgextend vg_centos3 ===Part 3: Practical Application - Compiling Source Code from Archive File==={| width="40%" align="right" cellpadding="10"|- valign="top"|colspan="2"|{{Admon/dev/vdbnote|Installing Development Libraries|In the future, remember the above procedure whenever installing software from source. Sometimes, you need to install additional tools or libraries in order to compile a particular software package}}
lvextend -L +2G -r vg_centos3/lv_root</code>|} <li>Now rerun the ls/pvs/vgs/lvs/df commandsthat you know how to create and decompress "zipped tarball archives", we will demonstrate how to install applications from websites containing these types of archives. What has changed and what caused those changes?</li> <li>Among Although this method is not as "user-friendly" as using the changesyum or rpm command, note that your root filesystem this method is useful if the application is now 2GB bigger - and you have not even rebooted your machine!</li></ol>NOT contained in regular software repositories...
'''Answer In order to build software from source code, you must have the Investigation 4 observations / questions appropriate software development tools (such as make and gcc) and libraries (such as GTK) installed. The required tools will vary depending on the computer languages used in your lab log bookthe software being built.'''
# Part is to be performed in your '''centos2''' VM.# Issue the following command to install a basic set of development tools and libraries:<br /><b><code><span style== Investigation 5"color: How is LVM managed using system#3366CC;font-config-lvm? ==size:1.2em;">yum groupinstall "Development Tools" "Development Libraries"</span></code></b><br><br>
'''Perform this investigation on the VM named ''<u>centos2</u>''.'''
[[Image:Ops235_lab4_1.png|thumb|right|Screenshot of system-config-lvm in CentOS. Click to enlarge.]]
# Let's learn to administer (manage) our LVM graphically for our '''centos2''' Virtual Machine.<br />CentOS provides a tool called <code>system-config-lvm</code> to graphically administer LVM. The package is not installed by default, so you will need to install it by issuing: (<code>yum install system-config-lvm</code>).
<ol>
<li value="2">Use this tool to determine the current LVM configuration by clicking on the appropriate element and reading the properties in the right-hand panel -- write down the answers:
<ol type="a">
<li>What are the names and sizes of the '''PV'''s?</li>
<li>What is the name and size of the '''VG'''?</li>
<li>What are the names and sizes of the '''LV'''s?</li>
<li>Is there any space in the VG which is not allocated to a LV?</li>
</ol>
</li>
<li>Increase the size of the home file-system to '''4 GB''':
<ol type="a">
<li>Click on the LV containing the '''home''' filesystem.</li>
<li>Click on ''Edit Properties''.</li>
<li>Change the size to '''4 GB''' and click ''Ok''.</li>
</ol>
<li>Create a '''new 3G LV''' (LV Properties: linear) containing an ext4 filesystem named lv_archive and mount it at '''/archive'''
<li>Backup <code>'''/etc'''</code> into <code>'''/archive'''</code></li>
</ol>
::* Copy the files in /etc into the filesystem mounted at <code>/archive</code><br />(use the graphical tools or the command line. If using cp, remember to use the -R option).
<ol>
<li value="3">Go to the directory '''/tmp'''</li> <li>Use the <b><code><span style="color:#3366CC;font-size:1.2em;">wget</span></code></b> command to download the "tar ball" that contains the source code for the NLED text editor. <code>wget</code> is a command-line tool to download files from the web using the http or ftp protocols. <ul> <li><b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">wget http://cdot.senecac.on.ca/software/nled/nled_2_52_src.tgz</span></code></b></li> </ul> </li> <li>Extract the files. Change to the newly-extracted directory (<b><code><span style="color:#3366CC;font-size:1.2em;">/tmp/nled-2.52</span></code></b>)</li> <li>Check to see if there is a file named <b><code><span style="color:#3366CC;font-size:1.2em;">configure</span></code></b>. If so, run it; if not, skip this step. (Most but not all source code archives contain this file)</li value> <li>Check to see if there is a file named <b><code><span style="color:#3366CC;font-size:1.2em;">Makefile</span></code></b> or <b><code><span style="6color:#3366CC;font-size:1.2em;">Shrink makefile</span></code></b>. If so, type the command: <ul> <li><b><code><span style="color:#3366CC;font-size of :1.2em;">make</span></code></b></li> <li>Did the command work? Why? Use the <b><code>lv_archive<span style="color:#3366CC;font-size:1.2em;">yum</span></code> </b> command to install the package '''1 GBgcc'''.What do you think the package ''gcc'' does?</li> </ul> <li>Reissue the <b><code><span style="color:#3366CC;font-size:1.2em;">make</span></code></b> command. Where you successful? What does <code>make</code> do?</li> <li>Issue the command as root: <b><code><span style="color:#3366CC;font-size:1.2em;">yum list ncurses</span></code></b>. What do you see? Issue the command at root: <b><code><span style="color:#3366CC;font-size:1.2em;">yum search ncurses</span></code></b>. What do you observe?</li> <li>In this case, you need to install the ncurses development libraries as well. Issue the following command as root: <b><code><span style="color:#3366CC;font-size:1.2em;">yum install ncurses-devel.x86_64</span></code></b>. Now issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">make</span></code></b></li> <li>Some software distributed as source code can automatically install itself. Try shrinking this command: <ul> <li><b><code><span style="color:#3366CC;font-size:1.2em;">make install</span></code></b></li> </ul> </li> <li>Most but not all source code archives include the home file-systemcapability of installing themselves this way. </li> <li>If the command <code>make install</code> does not work (how can you tell? What happenscommand did you learn from ULI101 to confirm that this command cannot be run from the command line? ), copy the <b><code><span style="color:#3366CC;font-size:1.2em;">nled</span></code></b> program manually: <ul> <li><b><code><span style="color:#3366CC;font-size:1.2em;">cp nled /usr/local/bin</span></code></b></li> </ul> </li> <li>Run <b><code><span style="color:#3366CC;font-size:1.2em;">nled</span></code></b> from the current directory to make sure that it works. To exit this application, press '''ESC''', then type the letter '''q''' at the command prompt as the bottom left-hand corner and then press '''ENTER'''.</li> <li>Whydid copying the nled executable to '''/usr/local/bin''' allow the nled command to be run by name anywhere in the command prompt?</li>
</ol>
'''Answer the Investigation 5 Part 3 observations / questions in your lab log book.'''
= Storage Setup (prior to starting Lab 4) INVESTIGATION 3: Using the Yum Command for Local & Repository Installs=
At this point, having completed [[OPS235 Lab 3 - CentOS6|Lab 3]] you should have <u>'''roughly'''</u> the following disk storage setup:<br />
('''Note:''' These results are output from the '''vgs''', '''lvs''', and '''pvs''' commands within each virtual machine. You will be using these commands in the following lab investigations)<br /><br />
* '''centos1'''== Manage Software and Repositories with Yum ==
This VM has a GUI and no free space in the VG.
VG #PV #LV #SN Attr VSize VFree
vg_centos1 1 2 0 wz--n- 9.80G 0
LV VG Attr LSize
lv_root vg_centos1 -wi-ao 8.83G
lv_swap vg_centos1 -wi-ao 992.00M
PV VG Fmt Attr PSize PFree
/dev/vda2 vg_centos1 lvm2 a- 9.80G 0
* '''centos2'''{| width="40%" align="right" cellpadding="10"|- valign="top"|colspan="2"|{{Admon/note|Internet Connection|In order for yum to work you require a connection to the Internet. Establish this connection by using the browser to log into SeneNET}}
This VM has a GUI and free space |}#Perform this section in your '''c7host''' machine.#Issue the VGcommand: <b><code><span style="color:#3366CC;font-size:1.2em;">yum install elinks</span></code></b> VG #PV Now issue the command: <b><code><span style="color:#LV #SN Attr VSize VFree vg_centos2 3366CC;font-size:1 4 0 wz--n- 19.51g 4.73g2em;">yum info elinks</span></code></b> #How can you tell if the elinks package has been installed? LV VG Attr LSize lv_archive vg_centos2 -wi-ao---#To remove the elinks package issue the command: <b><code><span style="color:#3366CC;font- size:1.00g 2em;">yum remove elinks</span></code></b># Verify that the elinks package has been removed. Also verify that the application called: '''xchat''' is not installed. lv_home vg_centos2 -wi-ao---- 4# Place your Centos7 Full Install DVD into the DVD drive of your hostmachine.00g lv_root vg_centos2 -wi-ao---- 7# View the contents of the DVD drive using the file manager application (called '''nautilus'''). Change to the Packages subdirectory.81g What does this subdirectory contain? lv_swap vg_centos2 # Use a graphical file manager to view the contents of the DVD in your machine.<br><br>'''TIP:''' If you are having problems locating pathname to your DVD, open a terminal, login as '''root''', issue the command: '''mount''', and look for a path-winame containing your Centos Install DVD and use that path-ao---- 1name when required later in this section.97g <br><br> PV VG Fmt Attr PSize PFree /dev/vda2 vg_centos2 lvm2 # Open ashell terminal and use the Linux command '''cd''' to change to the '''Packages''' sub-directory (hint: similar path-name as USB, but use '''Centos 7 x86_64/Packages''' and use '''quotes''' " " around full path- 19.51g 4name since there are spaces within the pathname).73g
* '''centos3'''{| width="40%" align="right" cellpadding="10"|- valign="top"|colspan="2"|{{Admon/note|A Note about Repositories|Since software repositories are on-line storage areas for software for particular Linux distributions, the Linux administrator can enable (add) or disable (remove) additional software repositories. Usually only the basic or "base" repositories are enabled upon Linux installation.}}|}
This VM has no GUI installed.
VG #PV #LV #SN Attr VSize VFree
vg_centos3 2 3 0 wz--n- 16.50g 0
LV VG Attr LSize
lv_home vg_centos3 -wi-ao---- 1.00g
lv_root vg_centos3 -wi-ao---- 10.00g
lv_swap vg_centos3 -wi-ao---- 992.00m
PV VG Fmt Attr PSize PFree
/dev/vda3 vg_centos3 lvm2 a-- 14.51g 2.54g
/dev/vdb vg_centos3 lvm2 a-- 2.00g 2.00g
* '''c6host (i.e. "disk pack")''':There are a few ways for yum to install applications:
/dev/sdc3 20G 3.7G 15G 20% /::* '''yum localinstall''' (install rpm files located from the machine via downloads to hard-drive, DVD, etc) /dev/sdc2 29G 4.7G 23G 18% /home /dev/sdc1 97G 48G 45G 52% /var/lib/libvirt/images::* '''yum install''' (install applications from an online repository)
= Logical Volume Management (Continued) =
{{Admon/note|Recovering VMs| <ol> <li value="11">Within the '''Packages'''Most subdirectory of these investigations will take place in you virtual machines.the '''Centos7 Full Install DVD''' If you make a significant mistake, your virtual machine may not bootlocate the '''rpm''' file that contains the '''xchat''' application (note the full path-name of the file). Remember that What do you created backups think is the purpose of your virtual machines the numbers also contained in Lab 3, and you can the filename?</li> <li>Issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">yum localinstall "full_pathname_to_xchat_rpm_file"</span></code></b></li> <li>Verify that the '''restore them if something goes wrongxchat'''command has been installed.}}</li></ol>
{| width="40%" align= Resources "right" cellpadding="10"|- valign="top"|colspan="2"|{{Admon/tip|IRCs: A Great Tool for Linux Administrators|Although Search Engines (like Google) are a system administrator's good friend, Internet Relay Chats (IRCs) are also a great tool for system administrators to help obtain information. Many website offer information on how to connect to IRCs (both nodes (eg. FreeNode) and irc channel (eg. #linux).<br><br><u>'''A few tips to consider with IRCs'''</u>:<ul><li>Do your Homework (read docs first!)</li><li>Ask specific questions</li><li>Not all chats are friendly</li><li>Be patient when asking questions (use courtesy)</li><li>The advise is free (you get what you pay for!)</ul>}}|}
Please read this page <ol><li value="14">We will now look at how we can add different repositories to our '''c7host''' machine.</li><li>As root, issue the following command: <b><code><span style="color:#3366CC;font-size:1.3em;">yum repolist</span></code></b></li><li>Take a few moments to view the contents of the file. Do you see which repositories are used by the '''yum''' command? Write down the repositories in your lab logbook.</li><li>View the following link to get an overview see a general listing of LVMrepositories:<br>[ [http://zenitwiki.centos.org/AdditionalResources/Repositories Available Repositories for Centos] ].</li><li>To add this repository, issue the command:<br><b><code><span style="color:#3366CC;font-size:1.3em;">wget https://dl.senecacfedoraproject.onorg/pub/epel/7/x86_64/e/epel-release-7-6.noarch.rpm</span></code> </b><br>Or if you receive a error message, try the command: <br><b><code><span style="color:#3366CC;font-size:1.3em;">yum install epel-release</span></code> </b></li><li>To enable the repository in yum, issue the following command:<br><b><code><span style="color:#3366CC;font-size:1.3em;">yum install epel-release-7-6.noarch.rpm</span></code></b></li><li>To clean-up the repository list (including downloading new applications in added repositories), issue the command: <b><code><span style="color:#3366CC;font-size:1.3em;">yum clean all</span></code></b></li><li>To verify that you have added the repository, you can issue the command: <b><code><span style="color:#3366CC;font-size:1.ca3em;">yum repolist</span></code></wikib></indexli><li>Unused and unneeded software can present a security risk and ties up disk space needlessly. Find '''at least 4 other packages''' to remove on your c7host machine(for example: '''sound & video''', '''games''', etc) that you're not using on your system.phpBe careful to ensure that removing those packages does not also remove other software that you do need.</Logical_Volume_Management Logical Volume Management]li></ol>
It is recommended to open another window(eg. '''right-click''', '''open in new tab or window''') to make reference to view LVM commands as you perform investigations 1 to 3.
== Investigation 1: How are LVMs are managed using Command-Line Tools ==# You are going to repeat the same LVM management operations (as your did with the ''centos2'' VM Answer Investigation 3 observations / questions in '''lab3'''), but you will using command-line tools in the '''centos3''' VMyour lab log book. Since the centos3 VM only operates in command-line mode, you will need to refer to the '''"Logical Volume Management"''' link above.# Write down the exact commands used at each step, and record appropriate command output::: a. Determine the current LVM configuration using the <code>pvs</code>, <code>vgs</code>, and <code>lvs</code> commands.:: b.Grow the home filesystem to 2G using the command <code>lvextend</code> and <code>resize2fs</code>.:: c.Create a new 2G LV containing an ext4 filesystem and mount it at /archive (use <code>mkdir</code>, <code>lvcreate</code>, <code>mkfs</code>, <code>mount</code>, edit the file <code>/etc/fstab</code> (read the resource: [https://wiki.archlinux.org/index.php/fstab https://wiki.archlinux.org/index.php/fstab] ), and then reboot to confirm automatic mount).:: d.Copy the contents of <code>/etc</code> into <code>/archive</code>.:: e.Shrink <code>lv_archive</code> to 1G (use <code>umount</code>, <code>resize2fs</code>, <code>lvreduce</code>, and <code>mount</code>)
== Investigation 2INVESTIGATION 3: How can a PV be added to an existing VG using Command-Line Tools? =LOOKING AHEAD =# Add an additional 2 GB virtual disk to your ''<u>centos1</u>'' system, we will use it as an additional physical volume.# Do the rest of this investigation in the command line.# You should now have both <code>/dev/vda</code> and <code>/dev/vdb</code>.# Record the size of the volume group and the amount of free space (Hint: use a command that you learned in a previous lab).# Read the resource [http://tldp.org/HOWTO/Partition/fdisk_partitioning.html Partitioning with fdisk] to learn how to properly create a partition with the fdisk command.# Use fdisk to partition /dev/vdb with a Linux single partition that fills the whole disk.# Check the messages printed when <code>fdisk</code> exits -- you may need to reboot the system in order for the new partition table to take effect.# Mark ''vdb1'' as a physical volume usable by LVM.# Add the new physical volume to the existing volume group.# Verify that the volume group is larger and has more free space.
==Automating Routine Tasks (Shell Scripting)=={|width="40%" align="right" cellpadding="10"|- valign="top"|{{Admon/notetip|Think!Bash Shell Scripting Tips:|<br><ul><li>'''The next part Here Document'''<br><br>A neat little trick involving a special type of this investigation requires some researchredirection of stdin ( '''<<''' ) that allows input to be redirected to a command from within the command. '''The name relates to where the stdin is contained: not in a file, thought, and creativitybut "here in the command itself"'''. A character (like '''+''') is used to mark the boundary of stdin.}}It is important that the ending boundary only contains a line with that matching character (eg '''+'''Using ); otherwise the stdin will continue to be read! This command is a convenience way to display multiple lines on that additional spacescreen, create but this command can be used with any Linux command that accept stdin.<br><br><u>'''Examples''' (try at the shell prompt)</u><br><br>''cat <<+<br>This is a separate filesystem for test message<br>This is the second line<br>+''<br><br>''mail -s "test message" youremailaddr <<+<br>This is a test message<br>I hope you like it.''<br>+<br><br>''tr [a-z] [A-Z] <<+<br>i like ops235<br>i love scripting.<br>+''<br><codebr></homeli><li>'''Using sed to Manipulate Text'''<br></codebr>The Linux command '''sed''' stands for <u>:'''# Create the logical volume S'''</u>treaming <codeu>lv_home'''Ed'''</codeu> itor which is an effective way to manipulate a text file, output sent from a command, or from within a "here document". This command can manipulate matching text on a variety of criteria (1G ext4such as line number, regular expression match, etc)# Find . Commands can then be used for manipulation such as omitting, printing, substituting, adding, inserting, etc. The sed option -n suppresses display of text so the print (p) command can be used; otherwise, the text will be displayed (with edits via the sed command instructions). Results of text manipulation with sed can be stored in a variable using command substitution, or redirected to a file. NEVER redirect the stdout from a way sed command to move the contents of same input file (or the input file will be destroyed)! <br><codebr></homeli><li>'''<u>Examples''' (try at the shell prompt)</codeu><br><br> onto it.''sed 's/|/ /g' <<+<br>I|like&# Change your system configuration so that the new filesystem is mounted on 124;weekends!<br>+''<br><br>''sed 's/$/\n/g' <<+<br>This text<br>should be<br>double-spaced!''<br>+<br><codebr></homeli></codeul> from now on.}}|}
{{Admon/tip|SELinux relabelling may be required|Your system may report that the files are not present in the new /home filesystem when they are clearly there. This is due to the Security-Enhanced Linux system (SELinux) preventing access to the files, because the files were tampered with (moved) and are no longer recognized as home directory content. You can fix this problem by restoring the file context labels so that SELinux accepts the files as valid home directory content: <code>restorecon -r /home</code>}}
== Investigation 3: How can I use fdisk We will continue with using shell scripts to manage storage on my disk pack? ==create a Software Information Report that manipulates output generated by the '''On your <u>c6host</u> (irpm''' command.e. "disk pack"), using your choice of the GUI and/or command-line tools:The '''sed'''# Create a new partition or logical drive (and '''NOT a logical volume!awk''') - minimum 5G, leaving at least 10G free space commands are very useful tools in the extended partitionshell scripting to manipulate text.# Format that partition (i.e. put a filesystem on it).# Make sure itIn this lab, we will be using ''sed''s mounted automatically on a mountpoint of your choosing to allow the user to select certain portions from the rpm command (easiest is to create a new directory for a mountpointoptions -qi).
If you require <u>'''additional practice'''</u> in creating shell scripts using the "sed" utility, run the following command in your '''Matrix''' account:<br>'''/home/murray.saul/scripting-4'''<br><br># Perform the following steps in your '''c7host''' machine for this section.# Open a Bash shell terminal and login as root.# Use a text editor (such as <b><code><span style= Updated backup "color:#3366CC;font-size:1.2em;">vi</span></code></b> or <b><code><span style="color:#3366CC;font-size:1.2em;">nano</span></code></b>) to create a Bash Shell script called: <b><code><span style="color:#3366CC;font-size:1.2em;">packageInfo.bash</span></code></b> in root's home directory.# Enter the following text content into your text-editing session:<code style="color:#3366CC;font-family:courier;font-size:.9em;margin-left:20px;"><br>#!/bin/bash <br><br># packageInfo.bash<br># Purpose: Generates a report to displaying specified information of installed software<br>#<br># USAGE: ./packageInfo.bash [application-name]<br>#<br># Author: *** INSERT YOUR NAME ***<br># Date: *** CURRENT DATE ***<br><br>if [ $HOME != "/root" ] # only runs if logged in as root<br>then<br> echo "You must be logged in as root." >&2<br> exit 1<br>fi<br></code><br><ol><li value="4">Save your editing session, but remain in the text editor.</li><li>The code displayed below will require the user to include only one argument after the command (script) which will be the application name. The following code will also generate the report title and current date. Add the following code</li></ol><br><code style="color:#3366CC;font-family:courier;font-size:.9em;"> if [ $# -ne 1 ]<br>then<br> echo "Your command must have a application-name as argument" >&2<br> echo "USAGE: $0 [application-name]" >&2<br> exit 1<br>fi<br><br># Create report title (echo with -e option allows newline \n character to be used)<br>echo -e "\nSOFTWARE PACKAGE INFORMATION REPORT" > /root/package-info.txt <br>echo -e "Date: $(date +'%A %B %d, %Y (%H:%M:%p)')\n\n " >> /root/package-info.txt<br> </code><ol><li value="6">Save your editing session, but remain in the text editor.</li><li>The code displayed below uses a trick called the "Here Document" to redirect stdin from within the command (a quick way to display output on the screen). The read command will store the different information report items as words (separated by a space). The sed command used to convert the spaces to pipes (|) and stored into another variable. This allows the sed command to use extended regular expressions to print rpm elements that match those various patterns to be added to the report. Add the following code</li></ol><br><code style="color:#3366CC;font-family:courier;font-size:.9em;"># Clear screen and use Here Document to display select on report items to read into variable<br>clear<br>cat <<+<br>Available Package Information Items:<br><br>Name<br>Summary<br>Version<br>License<br>Source<br>URL<br>+<br>read -p "Enter word(s) shown above separated by spaces: " choice<br><br># Convert spaces to pipe symbol (|)<br>processedChoice=$(echo $choice | sed 's/ /|/g')<br><br># Use sed with extended regular expressions to only print those matching report elements<br>rpm -qi $1 | sed -r -n "/($processedChoice)/ p" >> /root/package-info.txt<br><br>cat <<+<br>File "/root/package-info.txt" has been created<br>+<br></code> <ol><li value="8">Save, set permissions, and then run that shell script for the application '''gedit'''. Did it create that report? Try running the script without an argument - What did it do? <li>Use the <b><code>wget</code></b> command to download, study, and run the following shell scripts on-line:<blockquote><b><code><span style=" pointer-events:none;cursor:default;color:#3366CC;font-size:1.2em;">https://scs.senecac.on.ca/~murray.saul/packageInfoGraphical.bash</span></code></b></blockquote></li><li>Try to understand what this Bash Shell script does.</li><li>You have completed lab3. Proceed to Completing The Lab, and follow the instructions =for "lab sign-off".</li></ol>
If you completed this '''Answer Investigation 3 observations / questions in your lab correctly - please make sure you are still making full backups of your virtual machineslog book.'''
Remember adding = LAB 3 SIGN-OFF (SHOW INSTRUCTOR) ={{Admon/important|Time for a new harddrive to centos3? You will need to back up that drive as well. backup!|If you don't - you will only have half successfully completed this lab, make a new backup of your virtual machines as well as your host machine backed up, which is of no use for a recovery.}}
= Completing '''Arrange proof of the lab =following on the screen:'''
{{Admon<ol><li><span style="color:green;font-size:1.5em;">✓</span> '''centos3''' VM:<blockquote><ul><li> '''Archived''' files created</li></ul></blockquote></li><li><span style="color:green;font-size:1.5em;">✓</span> '''c7host''' Machine:<blockquote><ul><li> '''Four unnecessary packages removed'''</li><li> '''xchat''' package installed</important|Time li><li> '''One repository added''' for a new backup!|If you have successfully completed this lab, make a new backup yum</li><li>Creation of your virtual machinesbash shell script called '''packageInfo.}}bash'''</li></ul></blockquote><li><span style="color:green;font-size:1.5em;">✓</span> '''Lab3''' log-book filled out.</li></ol>
'''Notes:'''
# rpm command options
# yum command options
# How to use pvs/vgs/lvs/df/pvcreate/vgextend/lvextend
# Answer to this question "What is the license of the nautilus package?"
'''Arrange evidence for each of these items on your screen== Practice For Quizzes, then ask your instructor to review them and sign off on the lab's completion:'''# elinks application removed on the host (disk pack - main system c6host).# Unnecessary/unused packages have been deleted (list at least 4Tests, and show that they are no longer installed).# Fresh backup of the virtual machines.Midterm & Final Exam ==
= Preparing #What is the purpose of booting into single-user mode?#List steps in order to boot into single-user mode#What is the difference between a .tgz file and a .tar.gz file? What do these stand for Quizzes =?#What is the purpose of a repository?#What is source code?#How do you build software from source code?#Which is preferred: installing from an RPM file, or installing from source code? Why?#What does yum do that rpm does not?#List the steps to install a package via rpm command.#List the steps to determine detailed information regarding an install package via rpm and yum commands.#List the steps to remove a package via rpm command.#List the steps to install a package using the yum command.#List the steps to remove a package using the yum command.
# What is a VG? PV? LV?
# What commands are used to determine VG / PV / LV information?
# What does yum do that rpm does not?
# List the steps to install a package via rpm command.
# List the steps to determine detailed information regarding an install package.
# List the steps to remove a package via rpm command.
# List the steps to install a package using the yum command.
# List the steps to remove a package using the yum command.
# What is the total size of the "main" VG on your system?
# How do you create a LV?
# How do you delete an LV?
# How would you increase the size of the root filesystem by 50 MB?
[[Category:OPS235]][[Category:OPS235 Labs]]
