Discussion on:

Replace SyncToy with FreeFileSync for your SMB backup needs

completly screwed up my computer!!!!

I've been using Synchredible which is also free and works very well. How about a comparison? https://www.ascomp.de/en/products/show/product/synchredible/tab/description

FreeFileSync works well, - much better than the finicky SyncToy, but just make sure you don't install the accompanying "monetization" software that comes embedded in the download package. Read the install wizard carefully to make sure you avoid this.

I know synctoy polluted your system with garbage files, I don't know if freefilesync does as well, but why bother when robocopy exists?

I have a PC I am backing up to my NAS drive. Looked at RoboCopy, but I didn't see an option to sync both ways. I wanted the option to be able to drop file on my NAS and see on my PC. SyncToy does give you bi-directional sync.

First line copies one way, second line copies the other way.

I had looked into using Robocopy for 2 way syncing and found that it is not possible to get true 2 way syncing. Here is an example of where this will not work:

1. Let's say you had sides Left and Right.
2. Your script first runs Robocopy from Left to Right and then from Right to Left using the /mir switch to try to simulate "2 way sync".
3. You add a file to the Right side and you run the script.
4. Under this scenario, since the file does not exist on the Left, the first operation which runs /mir from Left to Right will _delete_ the file from the Right side, when we actually wanted it to be added to the Left side (since we added it to the Right side).

However, if you've found another set of switches to accomplish this, I would be very interested to hear about it. It's always better to use built in tools

Just a straight copy back and forth will work.

If you do a straight copy both ways, i.e. do not use "/mir", it will not sync renames and deletions. Here are two examples below:

Rename problem (assuming no "/mir" switch - straight copy):
1. Let's say you have sides Left and Right. Let's also say your script first runs Robocopy from Left to Right, and then from Right to Left.
2. You create a file on the Right side called NewFile1.txt and you run the sync script. So now NewFile1.txt exists on both the Left and Right sides.
3. You now rename NewFile1.txt on the Left to NewFile2.txt and you run the sync script.
4. Under this scenario, while NewFile2.txt will be copied over to the Right side, NewFile1.txt will be copied from the Right side to the Left side and so you will end up with NewFile1.txt AND NewFile2.txt. If you have a program that supports bidirectional syncing, you would have only been left with NewFile2.txt

Delete problem (assuming no "/mir" switch - straight copy):
1. Let's again say you have sides Left and Right. Let's also again say your script first runs Robocopy from Left to Right, and then from Right to Left.
2. You create a file on the Left side called TempFile.txt and you run the sync script. So now TempFile.txt exists on both the Left and Right sides.
3. You now delete TempFile.txt on the Left side and you run the sync script.
4. Under this scenario, when the copy operation from Right to Left occurs, TempFile.txt will reappear on the Left side, even though you had deleted it. If you have a program that supports bidirectional syncing, TempFile.txt would have been deleted from both sides.

If you delete the file and resync, it will reappear.
I have never used freefilesync but I don't see how it could track deletions.

[I am unable to reply to Slayer's comment since it appears to be too deep, so I am replying to my thread]

Both SyncToy and FreeFileSync are able to do bidirectional syncing. They do this by maintaining a database of what changes exist at the time of the last sync (this is what those miscellaneous hidden files keep track of. At the next sync, it compares the current contents from the previous sync contents and makes decisions based on that. This is something that Robocopy is unable to do.

Makes sense now.

Thanks Jack - useful. A couple of ideas:
1. Filtering is very strong, and easily permanently excludes files and folders from backup.
2. I use Create Batch Job to back up a couple of specific folders (Current jobs and Email) to a skydrive folder in my OS partition, which is mirrored automatically in the skydrive cloud. If this is set as a daily task (via a bat file) in Task Scheduler, it occurs automatically every day. I guess it would work the same with Dropbox or other cloud backup solutions.

FreeFileSync is currently my favorite Windows backup tool as it lets me backup to a network location without a fuss. "Mirror" is the best option for a new user (especially one without a backup) to experiment with as it won't mess with your source files. I did experience some permissions errors that went away when I started it using "Run as Administrator."

I've got a raid 5 array in my home server with 5.4 tb of effective usable space. I wanted a backup solution that could mirror that data to a NAS also running raid 5.

The array in the server is just a file storage array, the OS is running of a SSD so abrely any files in use.

I tried 7 utilities including FreeFileSync and Synctoy.
Both did there job. FreeFileSync was just a lot better and faster at it. Synctoy would take a very long time to scan for changes and would create "tasks" on a per file basis to copy them to the NAS. FreeFileSync did the same task in barely a minute which a more or less 10 times faster compared to synctoy. Actual transfer speed were more or less the same though

Agree with Slayer_7. Use Robocopy. Part of Win Vista and later and can be added for Win XP. Mirror, sync, etc. Don't need any program to install or uninstall.
And I don't trust any application [free or not] that resorts to installing another damn toolbar that no one needs.

Jack has already listed all of the pros of the product. A few other pros and cons about FreeFileSync, and some comparisons with SyncToy. We had to look into a solution for our laptops a few months ago and so I had done some research on this (we ended up selecting FreeFileSync for our needs):

Pros:
1. The FreeFileSync author is very responsive to problems and questions. I once had a minor issue that I found, and the author released a beta version within a few hours, and a production version within a day.
2. This project is still in active development (SyncToy has not had an update in quite some time).
3. I was able to create a config file that used variables in it that I was able to use for ALL of my userbase. While SyncToy does some command line parameters, it does not for instance allow you to exclude specific folders with the command line (we can exclude specific files via the command line though).
4. Since we can use a common shared config file for FreeFileSync, it is also easy to push new exceptions/changes to the config file if needed. To do this via the command line, SyncToy would require you to recreate the folder pair (or manually edit the existing folder pair via the GUI).
5. Good logging - FreeFileSync records what new files were added, removed and changed. We had found a bug in SyncToy that if it is run from the command line, i.e. the GUI is not used, the log file does not store what files were added/removed. From a troubleshooting perspective, this was important for us.

Cons:
1. FreeFileSync does NOT sync the folder timestamp (note that it DOES sync the file timestamps though - just the folders are ignored). Unfortunately, the developer feels that this is not important nor reliable to sync and does not have any plans to implement this. I don't have a link for this right now, but for some of my scenarios, this is one reason why I can't use FreeFileSync. This is my only real problem with FreeFileSync. It's minor for most scenarios, but can be important depending on what the sync is intended for.

I'm looking for an application that will automatically choose the option that keeps both files and adds (2) to the name when copying directories where you run into files with same name.