User:Chris Tyler/draft/ops235lab

State when starting Lab 4

When you are done Lab 4 you should have the following disk storage setup:

• fedora1

 This VM has a GUI and no free space in the VG.

 VG         #PV #LV #SN Attr   VSize VFree
 vg_fedora1   1   2   0 wz--n- 9.80G    0

 LV      VG         Attr   LSize  
 lv_root vg_fedora1 -wi-ao   8.83G                                     
 lv_swap vg_fedora1 -wi-ao 992.00M                                     

 PV         VG         Fmt  Attr PSize PFree
 /dev/vda2  vg_fedora1 lvm2 a-   9.80G    0

• fedora2

 This VM has a GUI and free space in the VG.

 VG         #PV #LV #SN Attr   VSize VFree
 vg_fedora2   1   3   0 wz--n- 9.80G 3.95G

 LV      VG         Attr   LSize   
 lv_home vg_fedora2 -wi-ao 1000.00M                                     
 lv_root vg_fedora2 -wi-ao    3.91G                                     
 lv_swap vg_fedora2 -wi-ao  992.00M                                     

 PV         VG         Fmt  Attr PSize PFree
 /dev/vda2  vg_fedora2 lvm2 a-   9.80G 3.95G

• fedora3

 This VM has no GUI installed.

 VG         #PV #LV #SN Attr   VSize VFree
 vg_fedora3   1   3   0 wz--n- 9.80G 3.83G

 LV      VG         Attr   LSize  
 lv_home vg_fedora3 -wi-ao   1.00G                                     
 lv_root vg_fedora3 -wi-ao   4.00G                                     
 lv_swap vg_fedora3 -wi-ao 992.00M                                     

 PV         VG         Fmt  Attr PSize PFree
 /dev/vda2  vg_fedora3 lvm2 a-   9.80G 3.83G

• host (disk pack)

 Four PVs, minimum VG size 60G
 Single filesystem on vg_main/root, size 50G
 At least 10G available space in VG

 20% of disk space unallocated to any partition (min 15G)

Logical Volume Management

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:

• Logical Volume Management

Investigation 1: How are LVMs managed using system-config-lvm?

Perform this investigation on the VM named fedora2.

Screenshot of system-config-lvm in Fedora 12. Click to enlarge.

1. Fedora provides a tool called system-config-lvm to graphically administer LVM. It will appear on the menu as System>Administration>Logical Volume Management. Verify that this package is present, and install it if required.
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:
   • What are the names and sizes of the PVs?
   • What is the name and size of the VG?
   • What are the names and sizes of the LVs?
   • Is there any space in the VG which is not allocated to a LV?
3. Increase the size of the home filesystem to 2 GB:
   1. Click on the LV containing the home filesystem.
   2. Click on Edit Properties.
   3. Change the size to 2 GB and click Ok.
4. Create a new 2G LV containing an ext4 filesystem named lv_archive and mount it at /archive
   1. Click on Logical View.
   2. Click the Create New Logical Volume.
   3. Set the name, size, filesystem, and mount point.
   4. Click Ok.

• Backup /etc into /archive

1. 1. Copy the files in /etc into the filesystem mounted at /archive (use the graphical tools or the command line. If using cp, remember to use the -R option).

• Shrink the size of lv_archive to 1 GB.
• Try shrinking / -- what happens? Why?

Investigation 2: How are LVMs managed from the command line?

Repeat the operations from Investigation 1, using the virtual machine fedora3 (command-line tools only). Write down the exact commands used at each step:

1. Determine the current LVM configuration using the pvs, vgs, and lvs command.
2. Grow the home filesystem to 2G using the command lvextend and resize2fs.
3. Create a new 2G LV containing an ext4 filesystem and mount it at /archive (use lvcreate, mkfs, mount, edit the file /etc/fstab, and then reboot to confirm automatic mount).
4. Copy the contents of /etc into /archive.
5. Shrink lv_archive to 1G (use umount, resize2fs, lvreduce, resize2fs, and mount)

Investigation 3: How can a PV be added to an existing VG?

Add an additional 5 GB virtual disk to your fedora1 system, and use it as an additional physical volume:

1. Start virt-manager.
2. Shutdown fedora1 if it is running.
3. Open the console window for fedora1.
4. Select the menu option View>Details.
5. Click + Add Hardware
6. In the Adding Virtual Hardware window that appears, select a Hardware Type of storage and click Forward.
7. Select File (Disk Image) for the storage space. Click on the Browse button near the Location field, add a new volume (which creates a new file in /var/libvirt/images), then click New Volume.
8. Give the new virtual disk file a name of fedora1b, with a Max Capacity and Allocation of 2000 MB. Click Finish.
9. Select the new virtual disk file and click Choose Volume.
10. Select a device type of Virtio Disk.
11. Finish creating the new virtual disk.
12. Boot the system.

You should now have both /dev/vda and /dev/vdb.

1. Record the size of the volume group and the amount of free space.
2. Partition /dev/vdb with a single partion that fills the whole disk.
3. Run this command to format the physical volume: pvcreate /dev/vdb1
4. Add the new physical volume to the existing volume group: vgextend 'nameOfVolumeGroup /dev/vdb1
5. Verify that the volume group is larger and has more free space.

Think!
The next part of this investigation requires some research, thought, and creativity.

Using that additional space, create a separate filesystem for /home:

1. Create the logical volume lv_home (1G ext4)
2. Find a way to migrate the contents of /home onto it.
3. Change your system configuration so that the new filesystem is mounted on /home from now on.

Investigation 4: How can I use LVM to manage storage on my disk pack?

On your host (disk pack), using your choice of the GUI and/or command-line tools:

1. Create a new logical partition (NOT a logical volume!) - minimum 5G, leaving at least 10G free space in the extended partition.
2. Add that partition as a PV into the existing VG (using the commands you used in the previous investigation)
3. Grow the root filesystem to fill the available space (this will provide sufficient space for Investigation 5)

Package Management

• Keep existing content.

User/Group Management

• Keep existing content, add a requirement to create their Matrix user on fedora3 (forcing use of command-line tools).