Added detailed migration from CASTOR side.

doc/migration/migrationFromCASTOR.md

@@ -71,6 +71,30 @@ Any?
       2. Migrate new CTA data and CTA-repacked CASTOR data to CASTOR
    2. Remove immmutable flag from CTA files.
 
+## CASTOR side scenarios
+1. Stager shutdown means no read, no write, but move and delete are still possible (nameserver operations).
+
+Other scenario:
+1. Remove write rights for CASTOR
+    1. B/W lists in stager
+    2. archive route removal
+    3. Tapes marked readonly (FULL|RDONLY) (option new state/column in the DB)
+    4. Expriment commit to not change the files (we rely on this)
+2. ND import for CASTOR to CTA
+    1. import to EOS NS in parallel to next
+    2. import to CTA catalogue
+    3. Tapes in CTA are disabled
+    4. Tapes in CASTOR are readonly
+3. Switch ownership of tapes
+    1. Marked are exported in CASTOR
+    2. Mark tapes as readonly on CTA
+    3. Mark all files in CASTOR "EXPORTED" as in CTA
+4. Look in CASTOR NS logs for renames/delete (and apply to CTA?)
+5. Scan CASTOR NS for differences
+
+## Other requirements
+Monitoring of files on tape should be created in continuity with CASTOR's.
+
 ## Redirector and experiment workflow effects
 
 ## Rollback