I am administering a standalone user-authenticated Samba 4.3.11 server on Ubuntu 16.04, which is accessed by Windows 7 Pro and 10 Pro clients configured to cache offline files.

The question is, what is the difference between the following parameters for smb.conf:

(a) csc policy = manual [the default]

(b) csc policy = documents

(c) csc policy = programs

I haven't found anything distinguishing these parameters in two hours on Google. The smb.conf man page is cryptic, referencing Windows Server policies that no amount of research discerns corresponding concepts. The impression I have gleaned is that "manual" permits user-initiated (i.e., not automatic) file sync and that one or the other of "documents" or "programs" permits automatic file sync.

The Windows clients' Group Policy has been configured to sync at logon, logoff, and specified intervals but this does not occur, at least not obviously. Users can manually initiate syncs, however, consistent with my impression of the default setting.

Any thoughts on the distinctions among these parameters would be most welcome.

2 Answers 2


There is not much documentation on this topic at all. I also noticed that clients sometimes ignore this policy.

One thing I noticed in the past: if you use roaming profiles you have to disable csc policy on that share or weird things will happen (profiles do not sync, strange error messages on the client during profile sync)

AFAICT these parameters just tell the client what to do and won't change the server's behaviour in any way other then telling the client what csc policy is set for this share.

There are four valid values for csc policy. I will try to describe what I understood these parameters do:


Disable client-side caching of resources on this share.


Allow the client to decide settings for client-side caching of resources on this share.

documents and programs

Optimize the client-side caching for the use with documents or for the use of programs from this share.

  • It sounds as if the best one can do until more guidance is published, is to accept the default (i.e. = manual) and configure the clients. So, your impression is that manual means manual configuration of clients, not limiting syncing to occur only manually, correct? What is your impression of what "optimization" means in the context of documents or programs? Do you think that suggests either (a) some change in the server's behavior or (b) some sort of server-defined configuration of client behavior? And, what might that be?
    – ebsf
    Aug 9, 2018 at 13:24
  • AFAICT the csc policy setting does not change the servers behaviour at all. It just tells the client how to cache data. I don't know for sure what these optimizations actually are, but I know that this was invented in the late 90'ies, early 2000'nds. I actually doubt this is a sane optimization in today's world. Aug 10, 2018 at 14:55

Warning: Offline Files and multiple users receiving "Access is denied" during sync.

(at least for Windows 10) if folder redirection is enabled then that Offline Files sync for that location will be enabled.

imagine that you have set the \\computer\Users share server side to tell clients that it is to be cached [csc policy = documents] AND also have folder redirection enabled with Offline Files. ie;




if userA, userB or userC is logged in, Windows will cache the current respective user and the ENTIRE \\computer\Users\ location :- and most likely fail, as the current logged in user may not have access to all other sub folders of the parent \\computer\Users


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.