Cannot open directory "Y:\.systemfile".

[Mike DSM]

Hello,

Sorry, I tried searching the forum for "systemfile" and get 0 results.

I'm setting up a mirror copy of one HD to another within a D-Link DNS 323 NAS box (the first is named Z: and the second is named Y:). I configured the backup to exclude nothing except the defaults:
\System Volume Information\
\$Recycle.Bin\
\RECYCLER\
\RECYCLED\
*\desktop.ini
*\thumbs.db

On the root of both drives there is a hidden directory named ".systemfile". Since the backup will error with .systemfile as part of it (and hang for nearly an hour), I'm about to add it to the Exclude.

Windows Explorer reports it as 0 bytes, but I see that the date of both the Z: and Y: .systemfile folders are dated 09/07/17 which makes me wonder: Are they created by FFS? I've done some general web searching for ".systemfile" related to a DNS without luck.

Is the hidden ".systemfile" directory created by FFS?
If it's created by the DNS 323 does anyone know its purpose?
Is there any potential harm to leaving it out of the mirror backup?

Thank you,

Mike