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Is accessing files via a loopback share the same as using a local path?

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Question from a user (paraphrased): When we access a local file via loopback UNC path, is this the same as accessing via the local path? I mean, is  "C:myfoldera.txt" equal to "\myservermysharea.txt" or I'll be using TCP/IP in any way?

Answer from SMB developer: When accessing files over loopback, the initial connect and the metadata operations (open, query info, query directory, etc.) are sent over the loopback connection. However, once a file is open we detect it and forward reads/writes directly to the file system such that TCP/IP is not used. Thus there is some difference for metadata operations, but data operations (where the majority of the data is transferred) behave just like local access.

Comments

  • Anonymous
    January 01, 2003
    @DilipThis is for all versions of SMB.Only reads and writes go through this optimized local path, so all ACL parsing follows the regular loopback path, along with all metadata operations.
  • Anonymous
    January 01, 2003
    This is my question!!! I was the one who asked!!!By the way, since which Windows version is this true? I mean, is this a Windows Server 2012 new feature or things always has worked this way?
  • Anonymous
    January 01, 2003
    @rafaThis optimization was introduced with Windows Server 2003 / Windows XP SP1 and is included in all versions after that.
  • Anonymous
    January 27, 2013
    Is this for SMB 2.X AND SMB 3.0 both?Also in theory, the ACL parsing when going local or loopback is different?