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Smarter TimeStamp Detection

Posted: 25 Jan 2015 17:31
by Stef123
The added support for portable devices raises my hopes again to "fix" an old issue. To reproduce, please plug in any kind of device or storage that does not equal the file system of your local machine (mostly NTFS I assume). Let's take an external drive formatted to FAT32.

Now copy a few hundred pics onto that drive - from your local NTFS to FAT32.
Now run SyncSelect > Select Different. This will yield about 50% of files as different, even though XY itself has just copied them to the other side.

This results in tons of unnecessary copy operations and backups which take much longer than with other commanders, which are smart enough to handle this without redundant wear and tear.

Portable devices are slow to start with. And they come in a variety of formats other than NTFS. Good reasons to tackle this issue, or so I hope :roll:

Re: Smarter TimeStamp Detection

Posted: 27 Jan 2015 13:34
by admin
OK, try Sync Select in the next beta and see if it's fixed.

Re: Smarter TimeStamp Detection

Posted: 28 Jan 2015 04:47
by Stef123
Hm, repeated my quick and dirty test from above with 14.80.0215
Copied a folder from local NTFS to external FAT32 USB stick.
Ran SyncSelect > Select Different
Again, it flags roughly 50% as different :cry:

Re: Smarter TimeStamp Detection

Posted: 28 Jan 2015 08:09
by admin
OK, I had a wrong conception of the nature of the problem. Now I see there are small (and random) differences in the timestamps of the copied files. So what we need is a little tolerance when comparing the timestamps. From my tests it seems that *2 seconds* would be enough. So two timestamps that differ by 2 seconds would be seen as equal. Okay?

Re: Smarter TimeStamp Detection

Posted: 28 Jan 2015 09:56
by Stef123
Yep. That should do the trick. I've seen similar techniques elsewhere, like FreeCommander.

Re: Smarter TimeStamp Detection

Posted: 28 Jan 2015 10:40
by Marco
Stef123 wrote:Yep. That should do the trick. I've seen similar techniques elsewhere, like FreeCommander.
I confirm. Most backup softwares have this feature where they allow a 2-second difference between source and destination.
Check also robocopy and its /fft switch ( http://ss64.com/nt/robocopy.html )

Re: Smarter TimeStamp Detection

Posted: 28 Jan 2015 11:06
by Enternal
Do you think it would be good if the user can modify that 2 second value? It's better than revisiting this thing again in the future. xplorer2 did something like that too to avoid it happening. Obviously default is 2 seconds.

Re: Smarter TimeStamp Detection

Posted: 28 Jan 2015 11:27
by admin
Enternal wrote:Do you think it would be good if the user can modify that 2 second value? It's better than revisiting this thing again in the future. xplorer2 did something like that too to avoid it happening. Obviously default is 2 seconds.
I thought about this, but then I thought: One tweak less. It's easy to add this later if really necessary.

PS: Thought again and changed my mind. Tweak comes.

Re: Smarter TimeStamp Detection

Posted: 28 Jan 2015 15:01
by Stefan
admin wrote:
Enternal wrote:Do you think it would be good if the user can modify that 2 second value? It's better than revisiting this thing again in the future. xplorer2 did something like that too to avoid it happening. Obviously default is 2 seconds.
I thought about this, but then I thought: One tweak less. It's easy to add this later if really necessary.

PS: Thought again and changed my mind. Tweak comes.

Fine! :tup:

Then that should work for 'daylight saving time' issue also ( 18:12:34 <> 17:12:34 )


 

Re: Smarter TimeStamp Detection

Posted: 28 Jan 2015 15:05
by admin
Stefan wrote:Then that should work for 'daylight saving time' issue also ( 18:12:34 <> 17:12:34 ) 
Not necessary. This issue has been handled as well v14.80.0217. Hasn't it?

Re: Smarter TimeStamp Detection

Posted: 28 Jan 2015 16:53
by Stefan
admin wrote:Not necessary.
Ohh sorry, I just thought, simple something like "TimestampDiff=60" would be good for that issue.
This issue has been handled as well v14.80.0217. Hasn't it?
Ahh, I see now there is already something going on. Not tested yet, but *searchingformythumpdrive*.... later on.



 

Re: Smarter TimeStamp Detection

Posted: 28 Jan 2015 17:01
by Stef123
v14.80.0217 - again the same test as above.
Now it flags everything as different :veryconfused: seems like it works the other way round, at least it's not the 50% anymore :titter: we're getting closer ...

Re: Smarter TimeStamp Detection

Posted: 28 Jan 2015 19:02
by admin
Whoops, that was only close to perfection. :whistle: Upload later...

Re: Smarter TimeStamp Detection

Posted: 29 Jan 2015 14:31
by Stef123
Thanks. Just ran my first backup with real data, and sure enough, the time savings are SIGNIFICANT. This might even solve some performance complaints of other users. Can't wait to try it on network drives next week. :tup: