6.7. Insufficient Free Extents for a Logical Volume
You may get the error message "Insufficient free extents" when creating a logical volume when you think you have enough extents based on the output of the
vgdisplay or vgs commands. This is because these commands round figures to 2 decimal places to provide human-readable output. To specify exact size, use free physical extent count instead of some multiple of bytes to determine the size of the logical volume.
The
vgdisplay command, by default, includes this line of output that indicates the free physical extents.
# vgdisplay
--- Volume group ---
...
Free PE / Size 8780 / 34.30 GB
Alternately, you can use the
vg_free_count and vg_extent_count arguments of the vgs command to display the free extents and the total number of extents.
[root@tng3-1 ~]# vgs -o +vg_free_count,vg_extent_count
VG #PV #LV #SN Attr VSize VFree Free #Ext
testvg 2 0 0 wz--n- 34.30G 34.30G 8780 8780
With 8780 free physical extents, you can run the following command, using the lower-case l argument to use extents instead of bytes:
# lvcreate -l8780 -n testlv testvg
This uses all the free extents in the volume group.
# vgs -o +vg_free_count,vg_extent_count
VG #PV #LV #SN Attr VSize VFree Free #Ext
testvg 2 1 0 wz--n- 34.30G 0 0 8780
Alternately, you can extend the logical volume to use a percentage of the remaining free space in the volume group by using the
-l argument of the lvcreate command. For information, see Section 4.4.1.1, “Creating Linear Volumes”.
