Re: Mounted cifs share and repeat=watch bidirectional sync

On Thu, 9 Jan 2025 at 11:49, Laurent Guerard <[email protected]> wrote:
>
> Thanks for the info about the periodical sync ! The problem is that I'd like to have it immediate, which works from my local machine to the network but not the other way around... I could set it periodically in a very short time, but that seems a bit shady no ?

Yes, for now at least, it only works in one direction but this is not
related to any shortcoming in Unison. If you combine the
watch+<seconds> then you still get the immediate sync from local to
network and a periodical sync from network to local. What is the best
interval for periodic sync, I can't say. It depends on your specific
conditions and resource availability. You can run tests with different
sync intervals and see how much the resources are strained. Depending
on your situation, I wouldn't be surprised if syncing every 5 seconds
is ok (relatively small replicas, fast disks where the Unison archive
is stored, low network latency). On the other hand, it may also be
that only a 5 minute interval is tolerable to you (large replicas over
a high-latency/low-bandwidth network, for example).

> Indeed, I'm using Linux and mounting a CIFS share, sorry, I should have been more precise. I wasn't aware of inotify, which makes it quite unfortunate if it doesn't work on cifs... Do you know if there's any way of using something else that might work on cifs ? If so what ? Thanks a lot for your help!

No, unfortunately I can't help any more here. Just know that Unison
uses inotify to get the change notifications on the client; you can
research using this knowledge or ask people better positioned to know
about Linux cifs mounts. Looking at Microsoft docs leads me to believe
that SMB version 3 definitely supports change notifications. A quick
search leads me to believe that also SMB 2 supports this. Assuming you
mount the share from a server that implements change notifications on
the server side then it is only the client's Linux kernel and/or cifs
driver that don't support it. Theoretically, it could work in the
future or with a different client driver.

To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].