Restructure and add note on boot disk size

docs/howto/operate/manual-nfs-setup.md

@@ -6,17 +6,7 @@ More information about the NFS Server can be found in {ref}`/topic/storage-layer
 ## Deploy the host Virtual Machine
 
 We need to first deploy a small virtual machine with a persistent disk that will host the NFS server.
-Using `gcloud`, the command is:
-
-```bash
-gcloud compute instances create nfs-server-01 \
-  --image=ubuntu-2004-focal-v20210720 \
-  --image-project=ubuntu-os-cloud \
-  --machine-type=g1-small \
-  --boot-disk-device-name=nfs-server-01 \
-  --boot-disk-size=100GB \
-  --boot-disk-type=pd-standard
-```
+You can use `gcloud` commands to achieve this.
 
 ````{note}
 To find the values of `--image` and `--image-project`, run the following:
@@ -34,6 +24,21 @@ gcloud computer images describe IMAGE_NAME --project=IMAGE_PROJECT
 ```
 ````
 
+```bash
+gcloud compute instances create nfs-server-01 \
+  --image=ubuntu-2004-focal-v20210720 \
+  --image-project=ubuntu-os-cloud \
+  --machine-type=g1-small \
+  --boot-disk-device-name=nfs-server-01 \
+  --boot-disk-size=100GB \
+  --boot-disk-type=pd-standard
+```
+
+````{note}
+The boot disk is where users' home directories and data are stored.
+Feel free to increase `--boot-disk-size` if 100GB won't be enough.
+````
+
 ```{note}
 If deploying a NFS server for a **private** cluster, add the `--no-address` flag to the `gcloud compute instances create` command.
 This will prevent the VM trying to claim an external IP address, which will not be allowed within the private configuration.