How to resize a root partition in GCP.
Increase disk size.
gcloud compute disks resize server-boot-disk-name \
--size=50GB \
--zone us-central1-c \
--project your-project-id
Run growpart.
growpart /dev/sda 1
Run xfs_growfs.
xfs_growfs /dev/sda1
To verify, run these.
lsblk
df -Th