Update maintenance.md

maintenance.md

@@ -104,3 +104,24 @@ Then try to restart the osd, this should clear the slow ops warnings.
 ```
 cephfs-journal-tool --rank=cephfs:all event get list
 ```
+### rados
+To get the object list on pool `ec22`:
+```
+rados -p ec22 ls
+```
+then to get the mapping into the OSDs you can to:
+```
+ceph osd map ec22 10000018bcc.00000000
+osdmap e24981 pool 'ec22' (26) object '10000018bcc.00000000' -> pg 26.72ac8a53 (26.253) -> up ([160,179,92,202], p160) acting ([160,179,92,202], p160)
+```
+In this case for our setup the OSD are located in:
+```
+160 -> cs-004
+179 -> cs-001
+92 -> cs-003
+202 -> cs-002
+```
+Losing `cs-001`
+```
+osdmap e24984 pool 'ec22' (26) object '10000018bcc.00000000' -> pg 26.72ac8a53 (26.253) -> up ([160,NONE,92,202], p160) acting ([160,NONE,92,202], p160)
+```