Installation guide

Creating Linear Logical Volumes

The following command creates a 1500 MB linear logical volume named testlv in the volume group

testvg, creating the block device /dev/testvg/testlv.

# lvcreate -L1500 -n testlv testvg

The following command creates a 50 gigabyte logical volume named gfslv from the free extents in

volume group vg0.

# lvcreate -L 50G -n gfslv vg0

You can use the -l argument of the lvcreate command to specify the size of the logical volume in

extents. You can also use this argument to specify the percentage of the volume group to use for the

logical volume. The following command creates a logical volume called mylv that uses 60% of the

total space in volume group testvol.

# lvcreate -l 60%VG -n mylv testvg

You can also use the -l argument of the lvcreate command to specify the percentage of the

remaining free space in a volume group as the size of the logical volume. The following command

creates a logical volume called yourlv that uses all of the unallocated space in the volume group

testvol.

# lvcreate -l 100%FREE -n yourlv testvg

You can use -l argument of the lvcreate command to create a logical volume that uses the entire

volume group. Another way to create a logical volume that uses the entire volume group is to use the

vgdisplay command to find the "Total PE" size and to use those results as input to the lvcreate

command.

The following commands create a logical volume called mylv that fills the volume group named

testvg.

# vgdisplay testvg | grep "Total PE"

Total PE 10230

# lvcreate -l 10230 testvg -n mylv

The underlying physical volumes used to create a logical volume can be important if the physical

volume needs to be removed, so you may need to consider this possibility when you create the logical

volume. For information on removing a physical volume from a volume group, see Section 4.3.6,

“Removing Physical Volumes from a Volume Group”.

To create a logical volume to be allocated from a specific physical volume in the volume group, specify

the physical volume or volumes at the end at the lvcreate command line. The following command

creates a logical volume named testlv in volume group testvg allocated from the physical volume

/dev/sdg1,

# lvcreate -L 1500 -ntestlv testvg /dev/sdg1