我在settings.py中的数据库设置如下

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'dbname',
        'USER': 'postgres',
        'PASSWORD': 'postgres',
        'HOST': '',
        'PORT':'8081',
    }
}

但是运行python manage.py
migration时出现错误django.db.utils.OperationalError：无法连接到服务器：没有这样的文件或目录

Traceback (most recent call last):
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/db/backends/base/base.py", line 130, in ensure_connection
    self.connect()
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/db/backends/base/base.py", line 119, in connect
    self.connection = self.get_new_connection(conn_params)
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/db/backends/postgresql_psycopg2/base.py", line 176, in get_new_connection
    connection = Database.connect(**conn_params)
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/psycopg2/__init__.py", line 164, in connect
    conn = _connect(dsn, connection_factory=connection_factory, async=async)
psycopg2.OperationalError: could not connect to server: No such file or directory
    Is the server running locally and accepting
    connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.8081"?


The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/core/management/__init__.py", line 338, in execute_from_command_line
    utility.execute()
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/core/management/__init__.py", line 330, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/core/management/base.py", line 393, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/core/management/base.py", line 444, in execute
    output = self.handle(*args, **options)
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/core/management/commands/migrate.py", line 93, in handle
    executor = MigrationExecutor(connection, self.migration_progress_callback)
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/db/migrations/executor.py", line 19, in __init__
    self.loader = MigrationLoader(self.connection)
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/db/migrations/loader.py", line 47, in __init__
    self.build_graph()
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/db/migrations/loader.py", line 182, in build_graph
    self.applied_migrations = recorder.applied_migrations()
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/db/migrations/recorder.py", line 59, in applied_migrations
    self.ensure_schema()
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/db/migrations/recorder.py", line 49, in ensure_schema
    if self.Migration._meta.db_table in self.connection.introspection.table_names(self.connection.cursor()):
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/db/backends/base/base.py", line 162, in cursor
    cursor = self.make_debug_cursor(self._cursor())
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/db/backends/base/base.py", line 135, in _cursor
    self.ensure_connection()
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/db/backends/base/base.py", line 130, in ensure_connection
    self.connect()
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/db/utils.py", line 97, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/utils/six.py", line 658, in reraise
    raise value.with_traceback(tb)
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/db/backends/base/base.py", line 130, in ensure_connection
    self.connect()
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/db/backends/base/base.py", line 119, in connect
    self.connection = self.get_new_connection(conn_params)
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/django/db/backends/postgresql_psycopg2/base.py", line 176, in get_new_connection
    connection = Database.connect(**conn_params)
  File "/home/vivekpradhan/joker/basket/local/lib/python3.4/site-packages/psycopg2/__init__.py", line 164, in connect
    conn = _connect(dsn, connection_factory=connection_factory, async=async)
django.db.utils.OperationalError: could not connect to server: No such file or directory
    Is the server running locally and accepting
    connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.8081"?

任何帮助将对您有所帮助，谢谢。我正在做一个ubantu操作系统。