Linux+ Logical Volume Management (LVM) Questions and Answers

Question 1

In the Logical Volume Management (LVM) hierarchy, which component serves as a pool of storage created from one or more Physical Volumes, from which Logical Volumes are then allocated?

Accepted Answer

Volume Group (VG)

Answer

Physical Extent (PE)

Answer

Logical Volume (LV)

Answer

Filesystem

Question 2

A system administrator needs to shrink a logical volume named `/dev/datavg/archives` from 100G to 80G. What is the most critical prerequisite step that MUST be performed *before* running the `lvreduce` command?

Accepted Answer

Resize the filesystem on the logical volume to be smaller than or equal to 80G.

Answer

Run `vgreduce` to ensure the Volume Group has sufficient free space.

Answer

Deactivate the logical volume using `lvchange -an`.

Answer

Create a temporary snapshot of the logical volume.

Question 3

A new disk, `/dev/sdd`, has been added to a server. A Linux administrator needs to add this disk's capacity to an existing Volume Group named `vg_data`. Which sequence of commands is the correct way to accomplish this?

Accepted Answer

1. `pvcreate /dev/sdd`
2. `vgextend vg_data /dev/sdd`

Answer

1. `lvcreate /dev/sdd`
2. `vgextend vg_data /dev/sdd`

Answer

1. `vgcreate vg_data /dev/sdd`

Answer

1. `pvcreate /dev/sdd`
2. `lvresize vg_data /dev/sdd`

Question 4

Which of the following commands is used to create a 5GB point-in-time snapshot named `webapp_backup` for the logical volume `/dev/vg_apps/lv_webapp`?

Accepted Answer

`lvcreate -s -L 5G -n webapp_backup /dev/vg_apps/lv_webapp`

Answer

`lvcreate -L 5G -n webapp_backup /dev/vg_apps/lv_webapp`

Answer

`snapcreate -L 5G -n webapp_backup /dev/vg_apps/lv_webapp`

Answer

`vgcreate -s -L 5G -n webapp_backup /dev/vg_apps/lv_webapp`

Question 5

A logical volume `/dev/vg01/lv_logs` is full. The volume group `vg01` has 20GB of free space. Which command will extend the logical volume to use all available free space in the volume group and resize its ext4 filesystem in a single operation?

Accepted Answer

`lvextend -l +100%FREE -r /dev/vg01/lv_logs`

Answer

`lvresize --size +100%FREE /dev/vg01/lv_logs && fsadm resize /dev/vg01/lv_logs`

Answer

`vgextend -l +100%FREE /dev/vg01/lv_logs`

Answer

`lvextend -L +20G /dev/vg01/lv_logs`

Question 6

Which command would you use to display a detailed, multi-line report of the attributes for a specific Physical Volume, such as `/dev/sda2`?

Accepted Answer

`pvdisplay /dev/sda2`

Answer

`pvs /dev/sda2`

Answer

`lvmdiskscan`

Answer

`vgdisplay /dev/sda2`