code: public void setRootPath(String path) throws CmsRfsException, CmsRuntimeException {
  
          checkFrozen();
  
          if (path != null) {
              // leading whitespace from CmsComboWidget causes exception
              path = path.trim();
          }
          if (CmsStringUtil.isEmpty(path)) {
              throw new CmsRfsException(
                  Messages.get().container(Messages.ERR_FILE_ARG_EMPTY_1, new Object[] {String.valueOf(path)}));
          }
          try {
              // just for validation :
              File file = new File(path);
              if (file.exists()) {
                  m_rootPath = file.getCanonicalPath();
              } else {
                  // if wrong configuration perform self healing:
                  if (OpenCms.getRunLevel() == OpenCms.RUNLEVEL_2_INITIALIZING) {
                      // this deletes the illegal entry
                      m_rootPath = new File(OpenCms.getSystemInfo().getLogFileRfsPath()).getParent();
                  } else {
  
                      throw new CmsRfsException(
                          Messages.get().container(
                              Messages.ERR_FILE_ARG_NOT_FOUND_1,
                              new Object[] {String.valueOf(path)}));
                  }
              }
          } catch (IOException ioex) {
              // if wrong configuration perform self healing:
              if (OpenCms.getRunLevel() == OpenCms.RUNLEVEL_2_INITIALIZING) {
                  // this deletes the illegal entry and will default to the log file path
                  m_rootPath = new File(OpenCms.getSystemInfo().getLogFileRfsPath()).getParent();
              } else {
  
                  throw new CmsRfsException(
                      Messages.get().container(Messages.ERR_FILE_ARG_ACCESS_1, new Object[] {String.valueOf(path)}),
                      ioex);
              }
          }
      }
docs: Set the path in the real file system that points to the folder/tree
  containing the log files.<p>
  
  This method will only success if the folder specified by the <code>path</code>
  argument is valid within the file system.<p>
  
  @param path the path in the real file system that points to the folder containing the log files
  
  @throws CmsRuntimeException if the configuration of this instance has been frozen
  @throws CmsRfsException if the given path is invalid