I would love some advice for my particular “want” with regard to backup software.
Here is the scenario I’m looking for—and it may be available in all the mentioned apps, but when I’ve read the product websites, I’ve not felt like it was clear (to me) that I could do this:
Folder A on my main drive, gets backed-up to Folder B on my backup drive.
When I make changes to Folder A, it gets updated in Folder B – if I update a File in Folder A, I want that file to REPLACE the same file in Folder B. If I add a folder inside Folder A, I want that folder ADDED to Folder B.
I DON’T WANT my entire drive backed up, only folders I specify.
I NEVER want anything from the backup drive to be deleted simply to make room for future updates (like TimeMachine does).
I NEVER want anything in Folder B on my backup drive to replace/overwrite anything in Folder A on my main drive
Now I’m guessing this is just one-way syncing, but I’m looking for someone with more experience using any of these apps to shed some light on the above.
That’s a straightforward one-way sync in Chronosync. I’d imagine no difference for other apps. Specify the two folders, set the nature of the sync to one way, can have it archive replacements so nothing is deleted from folder B. Set a calendar schedule. As long as the Mac is turned on and the drives are attached there’s little else to do bar the occasional check-in that all is well.
Perhaps you prefer a GUI app for this, but there is the free rsync included with every Mac that can be scripted to do exactly what you want. You define a list of folders to be backed up
where the -a flag means “archive” - it preserves permissions, file ownership, time stamps, etc. The -v flag is optional, but it provides a verbose output meaning that you can watch the files being synced. The -E flag means to honor and handle macOS metadata appropriately. Quotes and curly brackets are to protect spaces in source folder names.
You can set this up as a cron job to make sure it always runs in the background at certain intervals.
Rsync has a --delete option to remove from destination if deleted at source (which corresponds to what eg. TM would do), but it sounds like you’d prefer not to do that.
If I understand your want regarding folders, then Carbon Copy Cloner can handle that. In my case, I backup various music folders with different formats such as AIFF or mp3. Since I do make changes to a file sometimes due to metadata or album covers, I leave the SafetyNet option off since I do want the old files deleted and replaced with the new changes. In your case since you want to keep the old files with no deleting, you would leave the SafetyNet option on.
To set up the task, you simply drag the two folders to the appropriate windows and backup up manually or set up a schedule such as hourly, weekly etc. as appropriate to your needs.
CCC can do all of those things, but I believe the correct SafetyNet setting for what James is describing is “Don’t delete anything”. I use this setting for my photo archives. When I delete a project folder on the source, the archive of the project folder on the destination remains in place. Click on the “Destination” box, that’s where you will find the SafetyNet setting for the destination.
Thank you for the clarification! That is EXACTLY what I want. Essentially, to free-up space on the main drive by having files backed up to an external drive and then deleting them from the main drive.
It sounds like pretty much all the major apps offer what I’m looking for and it comes down to preferred GUI, price, and compatibility.
Now you’re saying you want to free up space on the main drive but you did not mention that in your initial post. Regardless, what I stated is still correct if you’re maintaining a true backup as SafetyNet will ignore other files on the destination drive which you might want to keep.
If SafetyNet is on, that folder on the destination is not going to be deleted.
From the program:
“When the SafetyNet is on, CCC places the older versions of modified files, and files that have been deleted from the source since a previous backup, into the _CCC SafetyNet folder at the root of the destination. We call this a “safety net” because the alternative would be to immediately delete those items. The SafetyNet prevents catastrophes — rather than immediately deleting items from the destination, CCC saves these items on the destination as long as space allows.
That third category of files and folders is left alone on the destination when the SafetyNet is enabled. Files and folders that are unique to the root level of the destination will be left completely alone.”
Now, I mostly use an older Version 5 with my music files so maybe whatever version your’re using has changed something so I can only speak to what I’ve used for years.
Sorry, I guess I thought it was implied because I don’t want the files/folders in Folder B (the backup drive) to ever be deleted. But yes, I’m looking to offload some (not all) files/folders from my main drive. It’s more for organizational purposes than space saving – though that’s always a welcome thing.
But it doesn’t really matter since CCC will warn you if you’re running out of space and then deletes older files from the SafetyNet folder only if you allow. Even if you have the Don’t Delete Anything option, it will warn you if space is a problem. At that point, it might be time for another backup drive.
Also consider having at least 2 copies of the archival storage. A single archive drive is a single point of failure. Having a second copy of the archive (essentially a backup of the archive) will reduce the chance of lost data should the original archive disk goes bad.
With the latest version of Chronosync, you don’t even need the calendar entry, you can schedule syncs based on a file change in a specified folder, as well as give it a minimum interval to run a sync regardless. I use that to get immediate backup of my active development folder to a server.