When multiple clients are connected to a NAS using SMB, access to the same file can overlap. For example, an unshared Excel file may show who currently has the file open, but these values may not have been adequately maintained.
Unfortunately, QNAP does not provide a way to get this information via the GUI, like the computer management of a Windows server, so we need the CLI. However, depending on the security settings, SSH access may need to be enabled first. For a QNAP, this setting can be found under “Telnet/SSH” in the control panel.
Then you can connect to the NAS using an SSH client (e.g. PuTTY) and execute the following command:
/usr/local/samba/bin/smbstatus -L