Summary of LVM
Logical Volume Manager (LVM) is a subsystem that allows you to use different areas of the same hard disk and/or areas from different hard disks as one logical volume. The size of file systems of logical volumes is not limited to one disk, as the volume can be located on different disks and partitions.
Main LVM designations:
- PV (Physical Volume) – partitions of disks or entire "unpartitioned" disks;
- VG (Volume Group) – a set of physical PV volumes combined to form a single disk;
- LV (Logical Volume) – partitions created on the physical space of the VG volume group.
LVM storage supports one virtual disk image format - RAW. Read more about LVM in the official documentation.
In VMmanager, LVM storage is used only for storing virtual machine (VM) disks. Each disk is stored in a separate LV with the name in the "<vm_id>_<vm_name>” format.
How to connect a storage
To connect the storage, enter Clusters → select the cluster → Network storages menu → :
- Press Add storage → Add a network storage → SAN.
- Specify its settings:
- Path to block device. For example, /dev/sdb.
- Press Add.
VMmanager will automatically configure the LVM storage on the block device: it will create PV and VG. If a VG has been created on the block device, the storage will not be connected.
Connecting the same storage to different clusters may damage the VMs.