doc: add dump stray folder command to the docs

Fixes: https://tracker.ceph.com/issues/56442
Signed-off-by: Igor Golikov <[email protected]>

Author: salieri11

doc/cephfs/scrub.rst

@@ -162,3 +162,30 @@ Evaluate strays using recursive scrub
   at root, run scrub with flags ``scrub_mdsdir`` and ``recursive``::
 
     ceph tell mds.<fsname>:0 scrub start / recursive,scrub_mdsdir
+
+Dump stray folder content
+=====================================
+
+- In order to dump stray folder content on a specific MDS, use the following command::
+
+    ceph tell mds.<fsname>:0 dump stray
+    {
+    "strays": [
+        {
+            "ino": "0x100000001f7",
+            "stray_prior_path": "/dir/dir1",
+            "client_caps": [
+                {
+                    "client_id": 4156,
+                    "pending": "pAsLsXsFscr",
+                    "issued": "pAsLsXsFscr",
+                    "wanted": "-",
+                    "last_sent": 3
+                }
+            ],
+            "loner": -1,
+            "want_loner": -1,
+            "mds_caps_wanted": [],
+            "is_subvolume": false
+        }
+    ]}