Update configuration.md

configuration.md

@@ -5,6 +5,10 @@
 ceph daemon /var/run/ceph/ceph-osd.22.asok config show | grep memory
 ceph daemon  osd.22 config set osd_memory_target 2147483648
 ```
+or you can inject parameter with 
+```
+ceph tell mon.\* injectargs '--mon-allow-pool-delete=true'
+```
 # Changing paramenters permanently
 Change the parameters on the admin `ceph.conf` file
 ```