Sometimes the VMs hosted on sourceware's bare-metal servers need more disk.

Recipe:

On host:

# lvresize -L +___G /dev/your_vg/your_lv
# virsh blockresize your_domain /dev/your_vg/your_lv --size 0
# virsh domblkinfo your_domain  /dev/your_vg/your_lv

On guest:

# See the new size
lsblk -f
fdisk -l

# Grow the partition (example: /dev/vda2 is the main partition; use growpart if available)
growpart /dev/vda 2   # or partx -u /dev/vda; or parted ; fdisk to delete/recreate partition (careful!)

# If LVM inside guest:
pvresize /dev/vda2
lvextend -l +100%FREE /dev/your_guest_vg/your_guest_lv   # or -L +xxG

# Depending on filesystem:
resize2fs /dev/your_guest_vg/your_guest_lv   # or /dev/vda2 if no guest LVM
xfs_growfs /mountpoint
btrfs filesystem resize max /