What are the restrictions on rsync backup?

What are the restrictions on rsync backup? -- Linux Enterprise Application-Linux server application information. For details, refer to the following section. Environment: Install cwrsync_server_2.0.10_installer.zip in win2003
Linux AS4 U2 installation rsync-2.6.3-1
Objective: To back up win2003 data to Linux
Test backup data: 3 GB

Run the command: # rsync-vzrtopg -- progress -- delete SvcwRsync @ win2003IP: test/backup
The following error occurs:
Sent 213664 bytes encoded ed 1443966415 bytes 2873990.21 bytes/sec
Total size is 2347349477 speedup is 1.63
Rsync error: some files cocould not be transferred (code 23) at main. c (1146)
Then the backup fails.
-- Rsyncd. conf --
Use chroot = false
Strict modes = false
Hosts allow = *
Log file = rsyncd. log
Pid file = rsyncd. pid

# Module definitions
# Remember cygwin naming conventions: c: \ work becomes/cygwin/c/work
#
[Test]
Path =/cygdrive/D/XXX/AA
Read only = false
Transfer logging = yes

Q: Are there any restrictions on rsync backup?
I couldn't find a reasonable explanation on the internet, saying it was a permission issue. I don't think so. CwRsync_Server is started by the SvcwRsync user, and SvcwRsync is also a Super User. In addition, the folder/backup permission used for backup is already 755.