Update Servers/Virtualization/Proxmox/Configuring iSCSI-based Cluster Storage.md

Servers/Virtualization/Proxmox/Configuring iSCSI-based Cluster Storage.md

@@ -214,21 +214,29 @@ vgscan
 !!! success
     If all validation tests pass, the storage is production-ready.
 
-# Cutover-specific commands, not relevant to commands above if you are setting everything up new without NFS being a pre-existing thing. 
+## Expanding iSCSI Storage (No Downtime)
+If you need to expand the storage space of the newly-created iSCSI LUN, you can run the ZFS commands seen below on the TrueNAS Core server.  The first command increases the size, the second command pre-allocated the space (thick-provisioned).
 
-## Decommission NFS (After Cutover)
-
-```sh
-zfs destroy CLUSTER-STORAGE/NFS-STORAGE
-```
-
-## Expand iSCSI Storage (No Downtime)
+!!! warning "ProxmoxVE Cluster Note"
+    `pvresize` must be executed on **exactly one** ProxmoxVE node.
+    All other nodes should only perform `pvscan` / `vgscan` after the resize.
+    Running `pvresize` on multiple nodes can corrupt shared LVM metadata.
 
 ```sh
 # Expand Zvol (TrueNAS)
 zfs set volsize=16T CLUSTER-STORAGE/iscsi-storage
 zfs set refreservation=16T CLUSTER-STORAGE/iscsi-storage
 
-# Rescan on Proxmox Nodes
+# Rescan the block device on all ProxmoxVE nodes
+echo 1 > /sys/class/block/sdX/device/rescan
+
+# Verify on all nodes that the new size is displayed
+lsblk /dev/sdX
+
+# Run this on only ONE of the ProxmoxVE nodes.
 pvresize /dev/sdX
+
+# Rescan on the other nodes that you did not run the pvresize command on.  They will now see the expanded free space.
+pvscan
+vgscan
 ```