12.7. Preventing the rounding error when creating an LVM volume
When creating an LVM logical volume, you can specify the number of logical extents of the logical volume to avoid rounding error.
Procédure
Find the number of free physical extents in the volume group:
# vgdisplay myvgExemple 12.5. Free extents in a volume group
For example, the following volume group has 8780 free physical extents:
--- Volume group --- VG Name myvg System ID Format lvm2 Metadata Areas 4 Metadata Sequence No 6 VG Access read/write [...] Free PE / Size 8780 / 34.30 GBCreate the logical volume. Enter the volume size in extents rather than bytes.
Exemple 12.6. Creating a logical volume by specifying the number of extents
# lvcreate --extents 8780 --name mylv myvgExemple 12.7. Creating a logical volume to occupy all the remaining space
Alternatively, you can extend the logical volume to use a percentage of the remaining free space in the volume group. For example:
# lvcreate --extents 100%FREE --name mylv myvg
Verification steps
Check the number of extents that the volume group now uses:
# vgs --options +vg_free_count,vg_extent_count VG #PV #LV #SN Attr VSize VFree Free #Ext myvg 2 1 0 wz--n- 34.30G 0 0 8780
