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?

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:
   • 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?

• Increase the size of the home filesystem to 2G.
  • Create a new 2G LV containing an ext4 filesystem named lv_archive and mount it at /archive
  • Backup /etc into /archive
  • Shrink lv_archive to 1G
  • Try shrinking / and observe that it is not permitted

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

• Repeat the operations from Investigation 1, using fedora3 (command-line tools only):
  • Determine the current LVM configuration.
  • Grow the home filesystem to 2G (lvextend, resize2fs)
  • Create a new 2G LV containing an ext4 filesystem and mount it at /archive (lvcreate, mkfs, mount, edit fstab, reboot to confirm automatic mount)
  • Backup /etc into /archive
  • Shrink lv_archive to 1G (umount, resize2fs, lvreduce, resize2fs, mount)
  • Try shrinking / and observe that it is not permitted

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

• Provision fedora1 with an additional 5G virtual disk
• Add that virtual disk to the existing volume group
• Create lv_home (1G), and migrate /home onto it (lvcreate, mkfs, mount, mv, rm, umount, edit fstab, mount)

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

• This investigation will have less-detailed instructions -- they students should be able to apply and adapt what they learned in the first three investigations.
• On the host (disk pack):
  • Create a new logical partition (minimum 5G, leaving at least 10G free space in the extended partition)
  • Add that partition as a PV into the existing VG
  • 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).