2 identical WD drives 4 TB each combine photos and compare: My question is what I think simple and Has only one acceptable answer for me at this time and that answer is yes. And MUST...

dyximan

My question is what I think simple and Has only one acceptable answer for me at this time and that answer is yes. And MUST be based on personal experience with the process and/or software to do so, again Personal experience. Does anyone know how to take the photos from 2 separate 4 TB WD drives and compare them to one another checking for and eliminating duplicates. I have a 2016 I Mac using Mojave the latest version

TriX Loc: Raleigh, NC

Are all the files/images on each drive in a single flat directory/folder, or are there multiple folders/layers on each drive?

catchlight.. Loc: Wisconsin USA- Halden Norway

TriX wrote:

Are all the files/images on each drive in a single flat directory/folder, or are there multiple folders/layers on each drive?

Use two computers, perhaps a laptop and a PC or two laptops...

Or open one file from one hard drive and minimize it then do the same with the second hard drive.Move them side by side and compare.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

dyximan wrote:

My question is what I think simple and Has only one acceptable answer for me at this time and that answer is yes. And MUST be based on personal experience with the process and/or software to do so, again Personal experience. Does anyone know how to take the photos from 2 separate 4 TB WD drives and compare them to one another checking for and eliminating duplicates. I have a 2016 I Mac using Mojave the latest version

In Windows I use the free application SyncBack Free. It has the ability to mirror drives, and lots of options like copying files that are missing on one drive to the other and vice versa. I am pretty sure that ChronoSync and Get Backup Pro both have similar capabilities.

If you don't want to pay for software, you can open up two sessions of Finder for each drive, and start by comparing space used, number of files on each, then a folder by folder comparison.

SeaBrat Loc: St Petersburg, FL

I use BeyondCompare in windows. It has a free trial version and works great. https://www.scootersoftware.com/

jerryc41 Loc: Catskill Mts of NY

Back in DOS days, there was a great little utility called DirComp. Specify the two directories, and it would compare the files.

These should work with two drives.
https://techguylabs.com/episodes/1339/how-can-i-compare-files-between-two-hard-drives
https://itstillworks.com/compare-files-two-hard-drives-7654485.html
https://www.experts-exchange.com/questions/26422570/Comparing-files-between-two-different-hard-drives-Finding-files-that-are-not-duplicated.html
http://techheavy.com/2011/05/compare-any-two-folders-side-by-side/
https://freefilesync.org/

TomV Loc: Annapolis, Maryland

Try Glary Utilties. Free version will do a duplicate files search. I just tested it out on my rig.

robertcbyrd Loc: 28754

I also use SyncBack Free. I'm lazy and it does the job.

AzPicLady Loc: Behind the camera!

SeaBrat wrote:

I use BeyondCompare in windows. It has a free trial version and works great. https://www.scootersoftware.com/

This is what one of my computer gurus uses. He showed me how it works. It will identify not only new files, but also those files to which changes have been made to one of the copies.

olemikey Loc: 6 mile creek, Spacecoast Florida

Side by side on a wide monitor works for me.

jhkfly

I don't know how Apple products work, but in MS Windows the process is amazingly simple and you don't need and specialized programs to compare files on different drives. I keep sets of the same photos on three different drives. I open each drive in a separate window side by side, locate the appropriate folder in each drive, set the "view" to show small images, and compare the pics horizontally. As all files are displayed in alphabetical or numerical order, any discrepancies are easily seen.

Hamltnblue Loc: Springfield PA

If the directories are the same, you could copy one drive to the other and then reverse.
If any are existing it will tell you and give options. Select skip and the all option and it will copy all files that do not exist.
Once done do so in reverse.
Best way though is to back up the drives. Then create a raid array using one of the 2 drives as the base.
After that you won't have to deal with keeping the drives matching.

TriX Loc: Raleigh, NC

Hamltnblue wrote:

If the directories are the same, you could copy one drive to the other and then reverse.
If any are existing it will tell you and give options. Select skip and the all option and it will copy all files that do not exist.
Once done do so in reverse.
Best way though is to back up the drives. Then create a raid array using one of the 2 drives as the base.
After that you won't have to deal with keeping the drives matching.

I agree - just copy one way and then reverse, selecting skip for duplicates, that’s why I asked about the directory structure.

nadelewitz Loc: Ithaca NY

Syncing programs give you choices about what to do:
1. Copying everything from drive a to drive B, without deleting anything from anywhere or;
2. Copying files from A to B and deleting anything on B that is not on A.

#2 is true syncing because old stuff deleted from A does not hang around forever on B.

But do #1 if you want WANT to keep everything you've ever done on drive B, for archival purposes, even after deleting old stuff on A (you want drive A to hold current data only).

It's up to you.

smf85 Loc: Freeport, IL

Easiest is do this from the command line

diff -rq directory1 directory2

This will compare the entire contents and the contents of all subdirectories in directory1 to the contents of directory2.

For a whole drive compare specify the logical device name for each directory, which can be found via the mount command.