Sesuai judul aja ya, waktu install proxmox nama nya ternyata gak sesuai dan pengen diubah, perintah dijalankan melalui putty/ssh, mari kita mulai :

1. stop semua guest pada node ybs
2. systemctl stop pve*
3. nano /etc/hostname
4. nano /etc/hosts
5. hostname {new_host_name}
6. hostname –ip-address
7. reboot
8. mv /etc/pve/nodes/{old_host_name}/lxc/* /etc/pve/nodes/{new_host_name}/lxc
9. mv /etc/pve/nodes/{old_host_name}/qemu-server/* /etc/pve/nodes/{new_host_name}/qemu-server
10. rm -r /etc/pve/nodes/{old_host_name}
11. login web proxmox

selamat mencoba..DWYOR!

sumber referensi :
(https://forum.proxmox.com/threads/rename-host-on-proxmox-5.35653/, https://www.solaris-cookbook.eu/virtualisation/proxmox-rename-standalone-node-hostname/)