Scriptable

/!\ Apply theses commands on each node of proxmox server /!\ My physical disk is /dev/sdb, please adapt for your case /!\ Remove VM or stop it before resize from Synology

1. Check the initial disk size

lsblk

1. Resize the LUN in SCSI manager from Synology DSM
2. Rescan the volumes and check again the right size of physical disk

iscsiadm --mode session --rescan 
lsblk

1. Resize the physical volume

pvresize /dev/sdb  

Enjoy !