Verify Copied Files as a GUI option

[mrfunky]

I know that we can turn on and off 'VerifyCopiedFiles' option in
GlobalSettings.xml file, but it's incredibly inconvenient to regularly change
this option by looking for this specific file on a hard drive (and it's not in
a nice place, but hidden in user files, where lovely windows puts plenty of
broken shortcuts to non existing folders, so navigating those waters is a
nightmare). I'm copying a lot of data regularly (100's of GB) and in most
cases I'm fine with no file verification (especially when it means faster
overall transfers), but sometimes when I need to copy work files I absolutely
need to use 'VerifyCopiedFiles' option. I've already had cases when an
external USB HDD connected through front PC panel randomly corrupted my data
during copying, and only thanks to FreeFileSync's 'compare by content' option
I could properly diagnose (and more importantly detect) this problem.

Therefore I want to ask if it is possible to simply add 'VerifyCopiedFiles'
option to GUI (for example in Advanced -> Global settings), so users can
decide whether they need higher speed or higher reliability. This option would
simply change 'VerifyCopiedFiles' option in GlobalSettings.xml to 'true' or
'false', so practically nothing would change in a program algorithms, only a
small, but very important, option would be added to GUI.

[Zenju]

Alright, I'll consider this for v3.14. It won't make it into next release
which is scheduled for this weekend.

[eddaso]

I love this program. I use it daily, and it really serves me well.

I just wanted to reiterate what mrfunky said. I have the exact same problem as
him, and I would really like to have file verification exposed in the UI.

For the time being, I've created a shortcut to GlobalSettings.xml on my
desktop, so I can right-click and edit the file from there, but man, it's a
pretty kludgy work-around.

Thanks.

[rgayler]

I'll add my vote to this please.

I have just started to use FFS for backup - so I want a paranoid approach. I
was going to abandon FFS because it appeared to not support verification after
copy. It is not mentioned in the feature list and I couldn't find it anywhere
in the Windows help.

Finding this thread was the only indication I had that FFS supported
verification and is what convinced me to stick with FFS.

So - I think you should put the verification option in the GUI because it is
more convenient and also because it advertises the existence of the feature
and some people will really care about it.

Thanks.

[Zenju]

I'm not too big a fan of the current implementation as it leaves gaps where
inconsistencies could occur, notably buffers at various levels of software and
hardware. I understand that I could put an option on GUI that proudly claims
to verify data and everybody would be happy and probably no questions would be
asked. But in truth keeping data consistent is not a trivial task and I don't
want to make false promises.

[beaker1024]

Along the lines of verifying files could FFS have an option to allow for CRC
checks? In my sinerio I hope to use a Windows Home Server Add-in "Integrity
Checker" that will automatically create and add CRC 160bit information
to each files alternate data stream ADS.

My first question is will FFS preserve the ADS information when it copies
files?

Secondly if the file has the information already in it's ADS can it be used to
do a verification? Sorry for being vague on this point I haven't started using
CRCs or this add-in yet.

I do see myself using FFS's batchs with log files (I love this feature and
setting them to a "Log" share on the server)

[Zenju]

> will FFS preserve the ADS information when it copies files?
I don't want to go so far and promise that it always will, but currently (and
since v1.0) it does copy ADS.

> can it be used to do a verification?
ADS is only supported for NTFS drives (well... basically). So this is a
functional restriction. Second issue is one has to keep CRC and file content
in sync.... big problem. Third, FFS doesn't need CRC for its tasks. The only
usecase where a given CRC might be useful is detection of renamed files... but
this is usually done via file ids instead.

[Zenju]

For future reference:
http://blogs.msdn.com/b/oldnewthing/archive/2012/09/19/10350645.aspx

[rvboutin]

Alright, I'll consider this for v3.14. It won't make it into next release
which is scheduled for this weekend.

Hi,
I am a big fan of FreeFileSync, and we are now at version 7.4 and I am still using version 5.21 in Ubuntu 12.04.5LTS, I would like to add my vote to have the option "VerifyCopiedFiles" available through the GUI.
I have copy for which it is not important and would slow down the copy unnecessarily but I have also batch copy of large file over network that I run overnight for which having it switched on would be great! Having to edit back and forth the configuration xml file is a bit of a pain to be honest.
Thanks for considering the suggestion!
Rv

[esumsea]

I too would welcome this option. I understand that sometimes checksums are verified from cache instead of the disk, but could there not be an option where after the files are copied/synced that they are checked against the source/disk? I have been encountering some corruption from copies/sync in several different programs. It is a very small percentage, among many terabytes, but every file is important. If there was a program that verified every file by content, it would be great. I know this program is supposed to do so, but when I run this function, comparing on content, I always get a different list of mismatches, even after all I have done is re-synced the files through FFS. Each time the list is different, even if slightly.