The full sequence for extending LVM

LVM extends online, at the cost of more steps, and skipping one wastes the whole exercise.

The disk has already grown (lsblk shows it):

pvresize /dev/vda2
vgs                      # confirm free space in the VG
lvextend -l +100%FREE /dev/vg0/lv_root
resize2fs /dev/vg0/lv_root      # ext4
# xfs_growfs /mount/point       # xfs

Order matters: physical volume sees the space, then the logical volume, then the filesystem.

Watch for: growpart first, or pvresize sees nothing new; XFS grows but never shrinks; and -l +100%FREE consumes everything in the VG, which leaves nothing for snapshots — use -L +10G if you need headroom.