Update 2-allocating_accessing.md

2-allocating_accessing.md

@@ -80,6 +80,10 @@ oarsub -l host=1/gpu=1 -I -t exotic
   ```bash
   oarsub -p "gpu_count = 2" -l host=3,walltime=2 -I
   ```
+  - reserved a node with 1 gpu for this demo, from 9h30 to 10h30
+    ```bash
+    oarsub -l gpu=1 -r "2021-12-10 09:30, 2021-12-10 10:30"
+    ```
 - Nodes with a specific CPU model:
   ```bash
   oarsub -p "cputype = 'Intel Xeon E5-2630 v4'" -l host=3,walltime=2 -I