#exDS# folder names in file backups of an NTFS

general discussion
1

Am I right to assume exDS stands for extended data stream and is urbackup’s way to store what I know as NTFS alternate data streams?
Either way, a mention of the mechanism to encode permissions and e.g. ntfs special attributes for storage on a posix fs in the documentation would be useful. When I evaluated urbackup I tried to create test-case files for this and it worked, but then one always has to wonder wether these files covered all the corner cases.

One more question; are ntfs permissions for files stored in the urbackup sqlite db or in special files along with the backups?

2

It uses the Windows Backup Api (BackupRead etc.) for files which should cover all corner cases and stores it into the files in the .hashes directory. Never saw #exDS# folders before.
Some attributes are handled separately as required (such as last modification time) and the permissions are also transformed into a UrBackup internal permission system (all stored in the files in .hashes).