Pause Button is not working!

[BruceH]

I am transferring a large number of relatively large files over a very slow VPN 1 Mb/s maximum speed connection. When I click on the pause button, the program says that it is paused, but it is still transferring data over the VPN as can be seen using Task Manager or Resource Monitor.
So I have no way to use the VPN temporarily for other tasks as the link is fully saturated with the file at 900Kbs transfer from FreeFileSync. I have tried leaving the pause button activated for long periods of time and the file transfers still continue in the background.

When I have tried the pause for a long period of time, I noted the number of files transferred and then when I un-paused the transfer I see that the number of files transferred has increased by 1, so it appears that it does not stop even if the current file has completed the transfer!

[xCSxXenon]

What is a "long time". There are a few things that it has to so before it can pause. On a 1mb/s connection, I could see it being an issue. I sometimes have to wait a few seconds even on gigabit local transfers.

[BruceH]

OK, I did another test and I paused the process at 4:32 PM today, at 5:06 PM the data was still transferring from the remote IP address as shown by resource monitor, I then took two screen shots one with it still paused then another a few seconds later after I continued the transfer.

2019-08-18 (1).png (21.02 KiB) Viewed 1456 times

2019-08-18 (2).png (21.12 KiB) Viewed 1456 times

You will notice that during the 34 minutes the transfer was paused the remaining amount changed from 681 MB to 499 MB, I think that pretty much proves that the transfer was still taking place.

If there is anything further that you would like to see, please let me know and I can provide it, I have many GB of files to transfer over this slow link and it is going to take days for it to completely transfer all the files.

[Plerry]

Likely FFS simply finished or was still busy synching a very large file it was syncing when you paused, but did not or would not start syncing a new file.

[xCSxXenon]

The two pictures do show the same file being transferred. I'm guess whatever you are syncing from/to does not handle pausing in the middle very well, or at all. I don't think FFS just stops, I believe that it requests a stop and then waits for a signal to do so. I would try syncing those files between two local folders and see if it pauses normally. That will tell you if the program is glitching out or the remote volume.

[BruceH]

OK I have done further testing on a local drive and here is what I am observing (which is the same as what is happening over my slow VPN WAN link).

I selected about six large files in FFS and set them to sync to another windows 10 computer on my network. I opened windows explorer to view the remote folder. I then started FFS and as soon as I saw the first temporary file was created in the remote folder I pressed the pause button. FFS then indicated that it was paused, I waited until Task manager showed that the file transfer had actually stopped. When I look at the remote folder it now shows 2 files have been synced, the one that had started when I pressed the pause button, plus one additional file that had not even started being processed when I pressed the pause button.

So it would appear that FFS will complete the current file plus one more before it actually pauses, perhaps not a big deal on fast networks, but a big problem when each file takes 30 or 40 minutes (or more) to transfer on a slow link.

Is FFS perhaps pre-processing the next file or is there a flaw in the pause logic?

[Zenju]

I can confirm the reported behavior: Currently "pause" means "do not take on any new work, but finish files that already started copying". This behavior is more or less an artifact of the multithreaded file copying infrastructure that was implemented a year ago. When copying lots of small files, this approach doesn't really make a difference, but when copying few large files it does. It seems improving "pause" (=> technically it's not trivial) is not the most critical feature, but it's on my TODO list.

[BruceH]

Thanks for confirming!

Perhaps an interim solution might be to have the message indicate that pause has been requested, instead of saying it has been paused when it really has not! I believe that that stop function works in this way.

Knowing that it works in this manner at least helps, for this particular scenario I may have to find another solution that allows on demand pausing of large file transfer in the interim! In all other regards the program meets my current needs and I will continue to use it for syncing files over my local network