Lvextend Command

Extend Logical Volume Size

The lvextend command is a powerful utility in Linux's Logical Volume Management (LVM) system used to increase the size of an existing logical volume (LV). This is crucial for managing disk space dynamically without repartitioning physical disks. This guide provides examples of how to use lvextend to expand your storage.

Common Lvextend Usage Examples

Here are several ways to utilize the lvextend command:

Extend by a Specific Size

To increase the size of a logical volume by a specific amount, use the -L option followed by a plus sign and the desired size (e.g., 10 Gigabytes).

# Extend a logical volume by a specific size (e.g., 10GB)
lvextend -L +10G /dev/vg_name/lv_name

Extend to a Specific Total Size

You can also extend a logical volume to a precise total size. This will set the LV to the specified size, potentially consuming space from the volume group.

# Extend a logical volume to a specific size (e.g., 50GB)
lvextend -L 50G /dev/vg_name/lv_name

Extend Using Available Free Space

To utilize all the remaining unallocated space within the volume group for a specific logical volume, use the -l +100%FREE option.

# Extend a logical volume using all the available space in the volume group
lvextend -l +100%FREE /dev/vg_name/lv_name

Extend on a Specific Physical Volume

In some advanced scenarios, you might want to extend a logical volume by allocating space from a particular physical volume (PV).

# Extend a logical volume on a specific physical volume
lvextend -L +5G /dev/vg_name/lv_name /dev/sdX

Resizing Filesystems After Extending

After extending a logical volume, you typically need to resize the filesystem residing on it to recognize the new space. The -r flag with lvextend can often do this automatically for supported filesystems.

Automatic Filesystem Resize

For common Linux filesystems like ext2, ext3, ext4, XFS, and Btrfs, the -r option attempts to resize the filesystem on the fly.

# Extend a logical volume and resize the filesystem on the fly (for ext2/ext3/ext4 file systems)
lvextend -r -L +10G /dev/vg_name/lv_name

# Extend a logical volume to use all the remaining unallocated space in the group and resize the filesystem
lvextend -r -l +100%FREE /dev/vg_name/lv_name

Manual Filesystem Resize Commands

If automatic resizing fails or is not supported for your filesystem, you can manually resize it using specific commands:

Ext4 Filesystem Resize

Use ext2resize for ext2, ext3, and ext4 filesystems. Note that ext2resize is a wrapper and often calls resize2fs.

# Extend ext4 filesystem after changing a logical volume
# (takes volume path as parameter):
ext2resize /dev/vg0/mylv

Btrfs Filesystem Resize

For Btrfs, use the btrfs filesystem resize command, specifying the mount point.

# Extend btrfs filesystem after changing a logical volume
# (takes the mount point as parameter, not the volume path):
btrfs filesystem resize max /mylv

XFS Filesystem Resize

Use xfs_growfs for XFS filesystems, also specifying the mount point.

# Extend xfs filesystem after changing a logical volume
# (takes the mount point as parameter, not the volume path):
xfs_growfs /mylv

JFS Filesystem Resize

For JFS, remounting with the resize option is typically sufficient.

# Extend jfs filesystem after changing a logical volume
# (takes the mount point as parameter, not the volume path);
# Just remount:
mount -o remount,resize /home

Lvextend Command - Extend Logical Volume Size | Online Free DevTools by Hexmos