Folder Comparison and Synchronization is not responding

Posts: 5 · ffennema1 7 Jan 2013, 20:35

I have run FFS in the past (v9 I think) successfully. Starting with V10 and V11, when I try to synch any files, FFS hangs (does not respond). In the synch window header is says "0.00% synchronizing ... not responding" and after about 55 seconds I get another pop up window with the message "Folder Comparison and Synchronization is not responding" and the options to Close the program or Wait for the program to respond. FFS never responds.

I have tried to just synch just a single text file from/to a pair of directories in my C:\Temp directory - same issue.

Only one version of FFS is running. I'm running Windows 7, 64 bit.

Any suggestions for getting this running again would be appreciated.

Posts: 7212 · Zenju 8 Jan 2013, 13:53

Is this problem consistently reproducible? If so I could create a debugging version of FFS and you could send me a stack trace for analysis, similar to:
[404, Invalid URL: https://sourceforge.net/p/freefilesync/bugs/223/]

Posts: 5 · ffennema1 9 Jan 2013, 19:08

Yes it's concistently reproducible. Thanks for your help in debugging this. Just let me know how to get your debugging version and what you want me to capture and how (minidump and stack trace?)

Posts: 7212 · Zenju 10 Jan 2013, 00:35

Okay, here's a debugging version of FFS 64 bit 5.11:
[404, Invalid URL: http://freefilesync.sourceforge.net/FFS_5.11_x64_debug.rar]
Then create a couple of minidumps (make sure to get at least one consistent one) with process explorer. If something's unclear see also the descriptions in the ticket above.

Posts: 5 · ffennema1 10 Jan 2013, 21:45

I have 2 dumps for you to look at however I tried to attach them (one at a time) using Add attachment in both IE and Firefox. Both browsers did not complete the post with the file. How can I get you these files?

Posts: 7212 · Zenju 10 Jan 2013, 21:50

Per email (see FFS's about dialog)

Posts: 5 · ffennema1 10 Jan 2013, 22:06

I'm uploading 2 files via SkyDrive now and sent you an email with a link. Thanks.

I've also asked the Source Forge folks to document any file size limit for the Add attachment function, which currently does not exist.

Posts: 7212 · Zenju 11 Jan 2013, 01:00

Thanks, here's the analysis: Both runs are stuck at checking the recycle bin existence for volume "C:\" which is implemented in terms of Win32 API SHQueryRecycleBin. Internally this traverses the whole content of the recycler on this drive.
So it looks like it is not hanging forever, but just busy. Could it be that your recycle bin is really large?

Posts: 5 · ffennema1 11 Jan 2013, 17:25

Yes, that is why it was taking so long. My recycle bin had over 7K files of 37GB worth of data. As soon as I emptied it, FFS started working again.

Thank you so much for helping me with this issue.

For others searching this forum with the same issue or problem, I've added the following text:

If FreeFileSync seems to hang or not respond make sure your recycle bin is not "too full" - just empty it!

Posts: 7212 · Zenju 11 Jan 2013, 17:48

There's also a todo for FFS: It must not block and should show a message like "checking recycle bin"...

Posts: 2 · darius80 10 Nov 2013, 21:21

Hi, i also get the "Folder Comparison and Synchronization is not responding" reproducably also with 5.23, when i sync folders with 100 large files (1GB) from internal hdd to external hdd.
It looks like it is reading from source drive faster than writing to target drive, and i suppose when read buffer runs full, freefilesync is not responding.
After some 10 seconds it is responding and reading again, starting at 10MB/s up until 150 MB/s then freeze again.

Posts: 7212 · Zenju 11 Nov 2013, 11:05

Hi, i also get the "Folder Comparison and Synchronization is not responding" reproducably also with 5.23, when i sync folders with 100 large files (1GB) from internal hdd to external hdd.
It looks like it is reading from source drive faster than writing to target drive, and i suppose when read buffer runs full, freefilesync is not responding.
After some 10 seconds it is responding and reading again, starting at 10MB/s up until 150 MB/s then freeze again.darius80

That's a common pattern seen with unbuffered storage devices like external USB memory sticks or HDDs. Unbuffered means that Windows does not buffer, since it expects that you could pull the plug at any time. However the storage device internally does buffer. And when it flushes the buffers it blocks the Windows drivers accessing it and thereby also FFS for a long time.

Posts: 2 · darius80 11 Nov 2013, 18:43

So FFS could do the driver access asynchron and the UI stays responsive?
The shown MB/s value could be the average value and hide the periodic blocked driver times while external drive flushing buffers.

Posts: 2 · rodot 17 Dec 2013, 03:13

That's a common pattern seen with unbuffered storage devices like external USB memory sticks or HDDs. Unbuffered means that Windows does not buffer, since it expects that you could pull the plug at any time. However the storage device internally does buffer. And when it flushes the buffers it blocks the Windows drivers accessing it and thereby also FFS for a long time.Zenju

I have the same problem, and as darius80 asked, could FFS do the driver access asynchronously and the UI stays responsive ?
It's making my computer unusable during sync as it keeps freezing...