Added extra information in logs.

- when failing to schedule.
- now list which drive has an existing mount (at schedule time as well.

scheduler/Scheduler.cpp

@@ -454,7 +454,8 @@ std::unique_ptr<TapeMount> Scheduler::getNextMount(const std::string &logicalLib
         tapesInUse.insert(em.vid);
         log::ScopedParamContainer params(lc);
         params.add("vid", em.vid)
-              .add("mountType", common::dataStructures::toString(em.type));
+              .add("mountType", common::dataStructures::toString(em.type))
+              .add("drive", em.driveName);
         lc.log(log::DEBUG,"In Scheduler::getNextMount(): tapeAlreadyInUse found.");
       }
     }

tapeserver/castor/tape/tapeserver/daemon/DataTransferSession.cpp

@@ -133,7 +133,8 @@ schedule:
   } catch (cta::exception::Exception & e) {
     cta::log::ScopedParamContainer localParams(lc);
     localParams.add("errorMessage", e.getMessageValue());
-    lc.log(cta::log::ERR, "Error while scheduling new mount. Putting the drive down.");
+    lc.log(cta::log::ERR, "Error while scheduling new mount. Putting the drive down. Stack trace follows.");
+    lc.logBacktrace(cta::log::ERR, e.backtrace());
     m_scheduler.reportDriveStatus(m_driveInfo, cta::common::dataStructures::MountType::NoMount, cta::common::dataStructures::DriveStatus::Down);
     cta::common::dataStructures::SecurityIdentity cliId;
     m_scheduler.setDesiredDriveState(cliId, m_driveConfig.unitName, false, false);