sync.ffs_db file

[evm]

Hi everybody,
I have 3 PCs (2*win7 and win8) and 1 NAS in my LAN and I need to sync 3 PCs MyDocuments folders for one particular user. The schema is:
PC1 <---------------> NAS <--------------> PC2
PC3 <-------------------^
So I installed FFS on PCs and create batch jobs for TwoWay sync for RealtimeSync. It seems to work fine but I see the sync.ffs_db file in the NAS folder which is not hidden.
Questions:
1. Is my schema ok for sync 3 PCs?
2. What is the purpose of sync.ffs_db file, why it is not hidden in NAS folder?
3. If 3 RealtimeSync processes work in the same time, what about the collision on sync.ffs_db in NAS folder? I mean if all FFS starts to write it in the same time.
Thanks,
George

[Plerry]

1) looks OK
2) required for FFS 2-way syncs. Why should it be hidden?
3) collision is prevented via the *.ffs_lock files
As soon as a FFS sync starts, it creates a ffs_lock file in the left and right location.
This tells other FFS process(es) that a sync is ongoing on that folder.
The other FFS process(es) then wait until the ffs_lock file is deleted,
which is done by active FFS sync process when it ends.

[evm]

1) OK :)
2) sync.ffs_db is hidden in PC's MyDocuments folder, but not in NAS Folder, so that was the reason of my question.
3) It is more clear now. So, sync.ffs_db on NAS folder will be accessed for write by only one PC's process in a time. OK, good!
Thanks, Plerry!

[Zenju]

2) sync.ffs_db is hidden in PC's MyDocuments folder, but not in NAS Folder

FFS tries to hide the file. Obviously something went wrong for the NAS folder, but it's not important, so no error message about it.

[evm]

FFS tries to hide the file. Obviously something went wrong for the NAS folder, but it's not important, so no error message about it.

My NAS is WD MyCloud model, it is accessed by SMB protocol and I think that is why FFS cannot make any file hidden.
Thank you, Zenju