I didn’t test it, but one approach can be:
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shutdown the node and resize its .qcow2 image from the host system:
sudo qemu-img resize ns8-green1.qcow2 +50G
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start the node and grow its 5th partition (remove -N, dry-run flag, when you’re confident):
growpart -N /dev/vda 5
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grow the root filesystem:
xfs_growfs /