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'''Answer the Investigation 5 observations / questions in your lab log book.'''
= Storage Setup (prior to starting Lab 4) =
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'''
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'''
This VM has a GUI and free space in 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
/dev/vda2 vg_centos2 lvm2 a-- 19.51g 4.73g
* '''centos3'''
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")'''
/dev/sdc3 20G 3.7G 15G 20% /
/dev/sdc2 29G 4.7G 23G 18% /home
/dev/sdc1 97G 48G 45G 52% /var/lib/libvirt/images
= Logical Volume Management (Continued) =
{{Admon/note|Recovering VMs|'''Most of these investigations will take place in 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, and you can '''restore them if something goes wrong'''.}}
== Resources ==
Please read this page to get an overview of LVM:
[http://zenit.senecac.on.ca/wiki/index.php/Logical_Volume_Management Logical Volume Management]
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 in '''lab3'''), but you will using command-line tools in the '''centos3''' VM. 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).
= Updated backup instructions =
