Talk:OPS235 Lab 4 - Fedora17

State when starting Lab 4

When the students are done lab 3, they should have:

• 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 (min 15G)

Recommendations for the revised Lab 4

LVMs

• Start with the GUI tool, which may help them visualize what is happening.
• Continue with performing exactly the same operations on another VM using command-line tools.
• Next, the will add a second virtual disk to a VM and migrate /home to its own filesystem.
• On the real system (disk pack), they will add a partition as a PV and grow the root filesystem (minimal risk).
• They will then migrate a VM from its original virtual disk to a new, slightly larger virtual disk. - Dropped because (a) it will take too long (close to an hour because the source and target are on the same physical drive) and (b) setting up grub on virtio drives is complex.

Recovering VMs
If the students encounter problems in Investigations 1-3 or 5, they can quickly restore their VM disk images from the backups created in Lab 3.

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

• On fedora2, perform some LVM operations using the system-config-lvm graphical tool:
  • Determine the current LVM configuration.
  • Grow 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).