Three-phase online resize: Proxmox qm resize → guest block device
rescan → drbdadm resize + xfs_growfs. No downtime required.
Detects active node via crm_mon, pre-checks DRBD UpToDate/UpToDate,
auto-discovers VMIDs from qm list, and resolves the block device name
from the stable scsi-0QEMU... by-id symlink with a slot-index fallback.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
