Create Logical Volumes with Lvcreate

The lvcreate command is a fundamental tool in the Linux Logical Volume Manager (LVM) suite, used for creating new logical volumes. Logical volumes provide a flexible layer of abstraction over physical storage, allowing for easier management of disk space, resizing, snapshots, and more. This guide provides essential examples of how to use lvcreate to manage your storage effectively.

Lvcreate Command Examples

Below are common use cases and examples for the lvcreate command:

Create a new logical volume with a specified size

This command creates a logical volume named my_lv within the volume group my_vg, allocating exactly 10 Gigabytes of space.

# lvcreate -L 10G -n my_lv my_vg

Create a logical volume using a percentage of the volume group

This example creates a logical volume that occupies 50% of the total available space in the volume group my_vg.

# lvcreate -l 50%VG -n my_lv my_vg

Create a mirror logical volume

This command creates a mirrored logical volume with two copies (one original and one mirror) for data redundancy, using 10 Gigabytes of space.

# lvcreate -m 1 -L 10G -n my_mirror_lv my_vg

Create a thin logical volume from a thin pool

Thin provisioning allows for over-allocation of storage. This command creates a thin logical volume my_thin_lv with a virtual size of 10GB, drawing space from the thin pool my_pool in my_vg.

# lvcreate -V 10G -T my_vg/my_pool -n my_thin_lv

Create a snapshot of an existing logical volume

Snapshots allow you to capture the state of a logical volume at a specific point in time. This creates a 5GB snapshot named my_snapshot of the logical volume /dev/my_vg/my_lv.

# lvcreate -L 5G -s -n my_snapshot /dev/my_vg/my_lv

Create a striped logical volume

Striping distributes data across multiple physical volumes to improve performance. This creates a striped logical volume my_striped_lv using 2 stripes and 10 Gigabytes of space.

# lvcreate -i 2 -L 10G -n my_striped_lv my_vg

Create a logical volume with specific physical volumes

This command creates a 10GB logical volume my_pv_lv, explicitly using /dev/sda1 and /dev/sdb1 as its underlying physical volumes.

# lvcreate -L 10G -n my_pv_lv my_vg /dev/sda1 /dev/sdb1

Create a logical volume with specific permissions

This command creates a 10GB logical volume my_lv with read-write (rw) permissions.

# lvcreate -L 10G -n my_lv -p rw my_vg

Create a logical volume specifying metadata size

This command creates a 10GB logical volume my_lv and explicitly sets the metadata size to 128MB.

# lvcreate --size 10G --name my_lv --poolmetadatasize 128M my_vg

Create a logical volume with zeroing of the first block

The -Z y option ensures that the first block of the logical volume is zeroed out upon creation, which can be useful for security or clean state initialization.

# lvcreate -Z y -L 10G -n my_lv my_vg

Clone an LVM volume

Cloning an LVM volume typically involves creating a mirror and then splitting it. This process ensures data integrity during the cloning operation.

# Clone LVM volume: test => testCopy
lvconvert --type mirror --alloc anywhere -m1 /dev/mylv/test
lvs -a -o +devices | grep -E "LV|test"
# After Cpy%Sync is 100% finished:
lvconvert --splitmirrors 1 --name testCopy /dev/rootvg/test

Further Reading

• lvcreate man page
• Red Hat LVM Management Documentation
• Linux Kernel LVM Documentation