This is biting me almost every time I startup a Zope instance with Plone sites in mounted storages. Don't know if it's relevant, but the filesystem on this box is quite slow.

Here are relevant bits from the log. Zope 2.9.9. 

2010-01-27T05:11:04 INFO ZServer HTTP server started at Wed Jan 27 05:11:04 2010
	Hostname: 0.0.0.0
	Port: 12101
------
2010-01-27T05:11:04 INFO ZServer ICP server started
	Address: 0.0.0.0
	Port: 7102
------
[...]
2010-01-27T05:11:33 INFO Zope Ready to handle requests
------
2010-01-27T05:11:33 INFO ZODB.lock_file locked <open file '/home/zope/instances/instance1/site-buildout_1.0.5/var/filestorage/siteData.fs.lock', mode 'r+' at 0xb714aa88>
------
2010-01-27T05:11:33 WARNING ZODB.lock_file failed to lock <open file '/home/zope/instances/instance1/site-buildout_1.0.5/var/filestorage/siteData.fs.lock', mode 'r+' at 0xb477e5c0>
------
2010-01-27T05:11:33 WARNING ZODB.lock_file failed to lock <open file '/home/zope/instances/instance1/site-buildout_1.0.5/var/filestorage/siteData.fs.lock', mode 'r+' at 0xb477e890>
------
2010-01-27T05:11:33 WARNING ZODB.lock_file failed to lock <open file '/home/zope/instances/instance1/site-buildout_1.0.5/var/filestorage/siteData.fs.lock', mode 'r+' at 0xb477e8d8>
------
[...] 
------
2010-01-27T05:14:32 ERROR Zope.ZODBMountPoint Failed to mount database. exceptions.OSError ([Errno 2] No such file or directory: '/home/zope/instances/instance1/site-buildout_1.0.5/var/filestorage/siteData.fs.lock')
Traceback (most recent call last):
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Products/ZODBMountPoint/MountedObject.py", line 257, in _getOrOpenObject
    conn = self._getMountedConnection(anyjar)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Products/ZODBMountPoint/MountedObject.py", line 147, in _getMountedConnection
    self._getDB()
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Products/ZODBMountPoint/MountedObject.py", line 157, in _getDB
    return getConfiguration().getDatabase(self._path)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Zope2/Startup/datatypes.py", line 280, in getDatabase
    db = factory.open(name, self.databases)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Zope2/Startup/datatypes.py", line 178, in open
    DB = self.createDB(database_name, databases)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Zope2/Startup/datatypes.py", line 175, in createDB
    return ZODBDatabase.open(self, databases)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/ZODB/config.py", line 107, in open
    storage.close()
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/ZODB/FileStorage/FileStorage.py", line 400, in close
    self._lock_file.close()
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/ZODB/lock_file.py", line 79, in close
    os.unlink(self._path)
OSError: [Errno 2] No such file or directory: '/home/zope/instances/instance1/site-buildout_1.0.5/var/filestorage/siteData.fs.lock'
------
2010-01-27T05:14:53 ERROR Zope.ZODBMountPoint Failed to mount database. exceptions.OSError ([Errno 2] No such file or directory: '/home/zope/instances/instance1/site-buildout_1.0.5/var/filestorage/siteData.fs.lock')
Traceback (most recent call last):
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Products/ZODBMountPoint/MountedObject.py", line 257, in _getOrOpenObject
    conn = self._getMountedConnection(anyjar)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Products/ZODBMountPoint/MountedObject.py", line 147, in _getMountedConnection
    self._getDB()
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Products/ZODBMountPoint/MountedObject.py", line 157, in _getDB
    return getConfiguration().getDatabase(self._path)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Zope2/Startup/datatypes.py", line 280, in getDatabase
    db = factory.open(name, self.databases)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Zope2/Startup/datatypes.py", line 178, in open
    DB = self.createDB(database_name, databases)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Zope2/Startup/datatypes.py", line 175, in createDB
    return ZODBDatabase.open(self, databases)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/ZODB/config.py", line 107, in open
    storage.close()
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/ZODB/FileStorage/FileStorage.py", line 400, in close
    self._lock_file.close()
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/ZODB/lock_file.py", line 79, in close
    os.unlink(self._path)
OSError: [Errno 2] No such file or directory: '/home/zope/instances/instance1/site-buildout_1.0.5/var/filestorage/siteData.fs.lock'
------
2010-01-27T05:15:02 ERROR Zope.ZODBMountPoint Failed to mount database. exceptions.ValueError (database_name 'site' already in databases)
Traceback (most recent call last):
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Products/ZODBMountPoint/MountedObject.py", line 257, in _getOrOpenObject
    conn = self._getMountedConnection(anyjar)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Products/ZODBMountPoint/MountedObject.py", line 147, in _getMountedConnection
    self._getDB()
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Products/ZODBMountPoint/MountedObject.py", line 157, in _getDB
    return getConfiguration().getDatabase(self._path)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Zope2/Startup/datatypes.py", line 280, in getDatabase
    db = factory.open(name, self.databases)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Zope2/Startup/datatypes.py", line 178, in open
    DB = self.createDB(database_name, databases)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/Zope2/Startup/datatypes.py", line 175, in createDB
    return ZODBDatabase.open(self, databases)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/ZODB/config.py", line 105, in open
    databases=databases)
  File "/home/zope/instances/instance1/site-buildout_1.0.5/parts/zope2/lib/python/ZODB/DB.py", line 262, in __init__
    raise ValueError("database_name %r already in databases" %
ValueError: database_name 'site' already in databases
------