macOS Sonoma 14.6, Time Machine re-backing up entire Photos Library frequently

Your Etrecheck report shows some oddities which I will point out but I do not fully understand:

• Mac performance is "below average." Something is bogging down the system, even Etrecheck took a long time to run.
• You have adware on your Mac.

Adware:

Launchd: ~/Library/LaunchAgents/com.appcart.AppCart.plist

Reason: Adware pattern match

Executable: ~/Library/Application Support/AppPolicy/AppCart

This could be related because adware sometimes writes files in various places, if it writes files on your drive with the Photos Library that could look like a modification which would mean Time Machine tries to back it up

• You have 13 (!!!) drives mounted.
• You have a Fusion drive in use, but it does not appear to be your boot drive???

disk3s1 - Macintosh HD [Fusion Drive] 2.00 TB (619.03 GB free)

APFS Mount point: /private/tmp/msu-target-ZanwC14d

I also don't understand the mount point. How have you set this up?

• I don't understand this:

System Software:

10.19.6 10.19.6 (23G93)

What MacOS are you running (version 10.19.6 what is that?) and from which drive?

• You have a utility called KeepDriveSpinning in use. My understanding of how these programs work is that they write small files onto the drives and keep the drive busy in that way. This could make it look like the volume where you large Photos Library is stored is modified when it really wasn't, triggering backups you don't need.

>>> Is this happening? I don't know. But I would start by uninstalling a lot of the many background tasks you have going to try to clean up the system. Etrecheck did say this: System modifications - There are a large number of system modifications running in the background. Low performance - EtreCheck report took over 5 minutes to run. This is unusual.

• What is this, is it some kind of security software tool? These are not advised, they often conflict ...

Launchd: /Library/LaunchDaemons/com.bresink.system.securityagent.plist

Executable: /Library/PrivilegedHelperTools/com.bresink.system.securityagent

• VPN is running, these are known to interfere with some MacOS processes
• Tunnelbear, another VPN is running
• Norton appears to be on this Mac, known to cause many MacOS anomalies
• Little Snitch is also there, also known to cause off behaviors
• You have an OlympusSSD driver, external drive tools and drivers are know to conflict with MacOS, could this be making small changes to your external drive(s) causing unnecessary backups to take place?
• Seagate toolkit also on this Mac, see previous comment, these utilities and drivers are known to be problematic, best to use external drives without them
• You are running Cocktail? Also a system modification, suspect ...

You have so many kexts and system modifications that I can't even go through them all. I suspect that the volume being backed up repeatedly is having files constantly written to it (I have pointed to some suspects above) and hence Time Machine things the whole volume is modified and needs backing up.

Frankly, I might consider making two verified backups and then wiping the system, doing a fresh install, then migrating your account and files only, then installing fresh only necessary apps.

Ken Shimabukuro wrote:

I know Time Machine is *supposed* to make incremental backups. What I'm saying is that it's not. For example right now Time Machine has backed up over 860GB of data, 92.8% done, 2 hours remains whereas 7 hours ago Time Machine said "About 20 minutes remaining." There is absolutely no way 860+ GB of data changed since the last backup completed last night.

Your previous post last month indicated that the issues were "fixed" but now the problem is back? If so, download and run the diagnostic Etrecheck. It is free and produces a report showing what is installed and running without revealing any personal information. I believe something installed is modifying the file system on the external drive and that tells Time Machine something changed and to back it up again. See this link for how to post the Etrecheck report.

How to use the Add Text Feature When Post… - Apple Community

How often do you back up? I was wondering before you posted the EtreCheck report and it shows you have turned off automatic backups.

There is a length of time between backups where it cannot do an incremental backup. Is it making a full backup of anything else?

macOS tracks file system events in a database. Those events are what is used to determine what has changed.

That database seems to only go back a couple of weeks. When you run out of valid change data, it does a full backup.

The Photos Library is a single package folder (that appears as a file) in your Pictures folder. Add, remove, or change one photo in it and that satisfies Time Machine's criteria that the Photos Library has changed and needs to be backed up. If it were a regular folder then only what changed would get backed up by Time Machine and not the whole folder.

VikingOSX wrote:

The Photos Library is a single package folder (that appears as a file) in your Pictures folder. Add, remove, or change one photo in it and that satisfies Time Machine's criteria that the Photos Library has changed and needs to be backed up. If it were a regular folder then only what changed would get backed up by Time Machine and not the whole folder.

My Time Machine doesn't re-backup the entire library, ever. Time Machine doesn't treat packages that way.

My Photos Library is around 48GB. Time Machine backed up this morning at 0530. I edited a numbers document and added some small videos to my Documents. I added a small image file to Photos. The backup ran, found about 1,000 items to backup, and copied about 2GB of data.

You should remove the Adware you installed. I'm pretty sure EtreCheck can help with that. But, I doubt that is your problem.

The most likely problems are caused by all of the junk ware you have installed to "maintain" your Mac. macOS doesn't need any maintenance and any software that purports to do so will just wreck the system.

Everything that purports to clean, optimize, protect, monitor, or otherwise maintain your Mac will only serve to cause problems, perhaps the one you are currently experiencing with Time Machine.