LVM Volume Group (vg)

commands related to managing Volume Groups (VGs) in LVM (Logical Volume Manager). Here's an overview of commands related to managing Volume Groups (vg) in LVM:

Volume Groups (VGs) in LVM manage one or more physical volumes (PVs) and provide logical storage units for Logical Volumes (LVs).

Basic Commands

1. Creating a Volume Group:

   vgcreate [options] vg_name /dev/sdX /dev/sdY ...

   Creates a new volume group named vg_name using physical volumes /dev/sdX, /dev/sdY, etc.

2. Displaying Volume Group Information:

   vgdisplay [vg_name]

   Displays information about all volume groups or a specific vg_name.

3. Adding Physical Volumes to a Volume Group:

   vgextend vg_name /dev/sdZ

   Adds /dev/sdZ to the existing volume group vg_name.

4. Removing Physical Volumes from a Volume Group:

   vgreduce vg_name /dev/sdZ

   Removes /dev/sdZ from the volume group vg_name.

5. Renaming a Volume Group:

   vgrename old_vg_name new_vg_name

   Renames old_vg_name to new_vg_name.

6. Removing a Volume Group:

   vgremove vg_name

   Removes the volume group vg_name.

7. Resizing a Volume Group:

   vgextend vg_name /dev/sdX

   Increases the size of the volume group vg_name by adding /dev/sdX.

Advanced Commands

1. Moving Physical Extents (PEs):

   pvmove /dev/sdX

   Moves allocated physical extents from /dev/sdX to other physical volumes in the volume group.

2. Changing Volume Group Attributes:

   vgchange -a y vg_name

   Activates (mounts) a volume group (-a y) or deactivates (-a n) it.

3. Listing Physical Volumes in a Volume Group:

   pvdisplay -m

   Lists detailed information about physical volumes and their mappings to logical volumes.

Conclusion

The vg commands in LVM (vgcreate, vgdisplay, vgextend, etc.) are essential for managing volume groups and the logical storage they provide. They allow administrators to efficiently allocate and manage disk space, resize volumes, and ensure data integrity through advanced features like mirroring and striping. For more detailed information and options, refer to the respective manual pages (man vgcreate, man vgdisplay, etc.) or the LVM documentation.