= Storage Setup (prior to starting Lab 4) Software Package Management =
At this point, having completed [[OPS235 Lab 3 - CentOS6|Lab 3]] == Investigation 1: How do 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 query the following lab investigations)<br /><br />RPM database? ==
RPM maintains a database of installed software. This information is very useful to system administrators. In the previous lab you queried that database using RPM with the -q argument. When you query the RPM database, you can separately specify::* Do an <u>operational task</u> on one or more packages (like installing or removing a package), using a '''centos1select-option''':* What <u>information</u> you want about those packages, using a '''query-option'''
This VM has a GUI and no free space in '''Perform 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 0following steps:'''
* '''centos2'''(Perform investigations 1 - 3 in your host machine (c6host)
This VM has a GUI and free space in # Using information from the VG. VG #PV #LV #SN Attr VSize VFree vg_centos2 1 4 0 wz--n- 19.51g 4.73g LV VG Attr LSize lv_archive vg_centos2 -wi-ao---- 1.00g lv_home vg_centos2 -wi-ao---- 4.00g lv_root vg_centos2 -wi-ao---- 7.81g lv_swap vg_centos2 -wi-ao---- 1.97g PV VG Fmt Attr PSize PFree man page for <code>rpm</dev/vda2 vg_centos2 lvm2 a-- 19.51g 4.73gcode>, fill in this information:
* '''centos3'''{|width="100%" border="1" cellpadding="5"|-!Option!Meaning!Select or query option?!Example command|-| -a|Select all packages|select-option| |-| -l| | | |-| -i|Show the package information.| | |-| -f filename| | | |-|packagename|Select just this package|select-option| |}
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---- '''Answer the Investigation 1.00g lv_root vg_centos3 -wi-ao---- 10.00g lv_swap vg_centos3 -wi-ao---- 992.00m PV VG Fmt Attr PSize PFree observations /dev/vda3 vg_centos3 lvm2 a-- 14.51g 2.54g /dev/vdb vg_centos3 lvm2 a-- 2.00g 2table contents in your lab log book.00g'''
* '''c6host (i.e. "disk pack")'''== Investigation 2: How do you install and remove software with RPM? ==
# Use the graphical file manager (Nautilus) to change to the directory on your Installation DVD. Go to the sub-directory called '''Packages'''. It should contain a file called: <code>lynx-2.8.6-27.el6.x86_64.rpm</devcode># Execute the following command: <code>rpm -i lynx-2.8.6-27.el6.x86_64.rpm</sdc3 20G 3code># Issue an RPM query to check that lynx is installed. Record this command in your lab log-book.7G 15G 20% # Issue the following command: <code>rpm -e lynx</code> /dev/sdc2 29G 4# Issue an RPM query to verify that lynx is no longer installed. Record this command in your lab log-book.7G 23G 18% /home /dev/sdc1 97G 48G 45G # Issue the following command: 52% <code>rpm -i elinks-0.12.rpm</var/lib/libvirt/imagescode>. Did it work? Explain in your lab log-book why this command may not have worked.
= Logical Volume Management (Continued) ='''Answer the Investigation 2 observations / questions in your lab log book.'''
{{Admon/note|Recovering VMs|'''Most of these investigations will take place in == Investigation 3: How do you virtual machines.''' If you make a significant mistake, your virtual machine may not boot. Remember that you created backups of your virtual machines in Lab 3, install and you can ''remove software with 'restore them if something goes wrong'yum''.}}? ==
== Resources =={{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}}
Please read this page # Change to get an overview of LVM:[http://zenityour home directory.senecac.on.ca/wiki/index.php/Logical_Volume_Management Logical Volume Management]
It is recommended <ol> <li value="2">Issue the command: <code>yum install elinks</code> and answer <code>y</code> to open another window(egthe question about installation. <ol type="a"> <li>Where did ''yum'right-click'get the elinks software?</li> <li>Why could '', yum''install elinks when rpm couldn'open t?</li> </ol> </li> <li>Issue an RPM query to verify that elinks is installed. Record this command in new tab or windowyour lab log-book.</li> <li>Issue the command: <code>yum remove elinks</code></li> <li>Issue an RPM query to verify that elinks is no longer installed. Record this command in your lab log-book.</li> <li>Issue this command: <code>yum info cups</code></li></ol>::* Based on the result, do you think that cups is a useful package for your system? If not, try removing it.<ol> <li value="8">Unused and unneeded software can present a security risk and ties up disk space needlessly. Find at least 4 other packages (for example: games, sound & video, etc) that you''') to make reference re not using on your system, and remove them. Be careful to view LVM commands as ensure that removing those packages does not also remove other software that you perform investigations 1 to 3do need.</li></ol>
== 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 the 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 2: How can a PV be added to an existing VG using Command-Line Tools? ==
# 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.
{{Admon/note|Think!|The next part of this investigation requires some research, thought, and creativity.}}
'''Using that additional space, create a separate filesystem for <code>/home</code>:'''
# Create the logical volume <code>lv_home</code> (1G ext4)
# Find a way to move the contents of <code>/home</code> onto it.
# Change your system configuration so that the new filesystem is mounted on <code>/home</code> 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 to manage storage on my disk pack? ==
'''On your <u>c6host</u> (i.e. "disk pack"), using your choice of the GUI and/or command-line tools:'''
# Create a new partition or logical drive ('''NOT a logical volume!''') - minimum 5G, leaving at least 10G free space in the extended partition.
# Format that partition (i.e. put a filesystem on it).
# Make sure it's mounted automatically on a mountpoint of your choosing (easiest is to create a new directory for a mountpoint).
= User/Group Management =