Understanding LVM

LVM uses three layers to manage the storage devices in our systems. These layers are as follows:

• Physical Volumes (PVs): The first layer of LVM. Assigned to the block devices directly. A physical volume can be either a partition on a disk or a full raw disk itself.
• Volume Groups (VGs): The second layer of LVM. It groups the physical volumes to aggregate space. This is an intermediate layer and not very visible, but its role is very important.
• Logical Volumes (LVs): The third layer of LVM. It distributes the space that the volume groups aggregate.

Let’s see the example that we want to implement using the two newly added disks:

Figure 13.4 – An example of LVM using two disks

Let’s explain this example diagram to understand all the layers:

• We have two disks, which are Disk1 and Disk2 in the diagram.
• Disk1 is partitioned into two partitions, Part1 and Part2.
• Disk2 is not partitioned.
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