LVM

TODOLVM functions by layering abstractions on top of physical storage devices. The basic layers that LVM uses, starting with the most primitive, are.

Physical Volumes:

LVM utility prefix: pv.... DOCUMENT THIS Description: Physical block devices or other disk-like devices (for example, other devices created by device mapper, like RAID arrays) are used by LVM as the raw building material for higher levels of abstraction. Physical volumes are regular storage devices. LVM writes a header to the device to allocate it for management. Volume Groups:

LVM utility prefix: vg... Description: LVM combines physical volumes into storage pools known as volume groups. Volume groups abstract the characteristics of the underlying devices and function as a unified logical device with combined storage capacity of the component physical volumes. Logical Volumes:

LVM utility prefix: lv... (generic

here'sLVM commands 

utilities might begin with lvm...) Description: A volume group can be sliced up into any number of logical volumes. Logical volumes are functionally equivalent to partitions on a physical disk, but with much more flexibility. Logical volumes are the primary component that users and applications will interact with.

Create a volume group

pvcreate /dev/sda1 /dev/sdb1
vgcreate vol_group_name /dev/sda1 /dev/sdb1
lvcreate -l 95%FREE -n drive_name vol_group_name

View info on group

pvscan
pvdisplay
vgdisplay
lvdisplay

Mount lvmLVM (Perfect for rescue)

sudo pvscan                 
sudo vgscan                 
sudo                 
vgchange -ay           
sudo lvscan    
sudo    
mount /dev/VolGroup00/LogVol00 /mnt

Full Doc:

http://xmodulo.com/use-lvm-linux.html https://www.digitalocean.com/community/tutorials/an-introduction-to-lvm-concepts-terminology-and-operations https://www.digitalocean.com/community/tutorials/how-to-use-lvm-to-manage-storage-devices-on-ubuntu-16-04