What is the difference between a 64-bit fileid and a 128-bit fileid in Windows?

[Christopher R. Hertel]

Richard,

The actual on-volume FileID, as used by NTFS and/or ReFS, is beyond my know-how.

If you are asking about the SMB2 FileId (the one returned and maintained by
the server), then see: [MS-SMB2; 2.2.14.1]

That section explains that the 128-bit FileId (as used in SMB2/3) is made up
of two 64-bit subfields:
* Persistent
* Volatile

As you probably know, the Persistent portion is maintained over (successful)
reconnects.  The Volatile portion can change.

I don't know if/how these are mapped to the on-disk FileIds that Windows
uses internally.

Chris -)-----


On 7/7/20 3:32 PM, Richard Sharpe via samba-technical wrote:
> Hi folks,
> 
> I have just become aware that Windows has both a 64-bit fileid and a
> 128-bit fileid.
> 
> https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-fscc/2d3333fe-fc98-4a6f-98a2-4bb805aff407
> https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-fscc/98860416-1caf-4c80-a9ab-8d61e1ccf5a5
> 
> Are they always equal if the fileid fits in 64 bits or are they different?
>