Move Proxmox Install To Different Drive

Install new SSD in the machine

Insert USB/CD to install PVE

During PVE installation, accept the rename of the old HDD pve volume group to pve–OLD–AAAAAAA

once installed, update, upgrade and reboot

sed -e 's//#/g' /etc/apt/sources.list.d/pve-enterprise.list echo "deb http://download.proxmox.com/debian/pve buster pve-no-subscription" > /etc/apt/sources.list.d/pve-no-subscription.list 
apt-get update 
apt-get dist-upgrade -y 
reboot

Mount old volume group, stop all pve service and copy conf files

OLD_VG=`vgs | grep OLD | awk -F" " '{print($1)}'`
mkdir /mnt/restore 
mount /dev/mapper/${OLD_V}-root /mnt/restore/
cd /mnt/restore/ 
cp -r old_etc /root/ 
systemctl stop pve* 


mkdir -p /root/deathstar_var/lib 
mv /var/lib/corosync /root/old_var/lib/ 
mv /var/lib/pve-manager /root/old_var/lib/ 
mv /var/lib/pve-cluster /root/old_var/lib/ 

cd /mnt/restore/var/lib
cp -rp corosync /var/lib/ 
cp -rp pve-manager /var/lib/ 
cp -rp pve-cluster /var/lib/

mv /etc /etc_install 
cp -rp /mnt/restore/etc /

reboot

hope this helps