Time Machine backing up too many files

A common complaint appears to be Time Machine taking too long. I notice that too. I notice it backs up giga-bytes everytime. I have excluded folders, of course. I dug further to look at the files on the backup disk to see what files are actually copied across. See the screen shot whjere I show a typical folder for yesterday’s backup. That drive goes back to backup folders since August this year. Note how these typical files some unchanged in many years appear to be backed up and copied to the backup folder by Time Machine.

I thought Time Machine takes an initial copy, then only takes new copies when updated? No? I’m guessing this a “feature” of TimeMachine and no way for me to resolve? Or is there a way?

I tore my hair out for quite some time with this. I suspect contributing factors to the problem are very large hard drives and local databases which are frequently updated.

I switched to Carbon Copy Cloner instead of Time Machine and instantly realized “Why didn’t I do this long ago?”

Time Machine is typical Apple design for the masses with very limited user control over the process. It does not scale well to large drives and workstations with very frequently changing data.

Thanks … but you’ll notice that none of the files I showed in the screen shot are local “databases” that changed (per dates on files on the backup drive). It’s a 2TB disk.

I’d of course prefer not to use Carbon Copy Cloner unless forced.

Looking for advice, should there be any, to use Time Machine and not hear how terrible it is (although it might be).

Are those old files aliases to the original copies?

Thanks for the reply. These are real files on an external disk and not aliases files back to the original files the Mac. Files created by Time Machine.

Howard Oakley provides The Time Machine Mechanic (T2M2) to observe and provide diagnostics as it watches Time Machine in operation. I haven’t used T2M2, but I trust Howard’s deep knowledge of macOS.

Some of his Time-Machine-related Mac troubleshooting posts might also be relevant.

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Thanks… I’ll look at Howard’s material.

I just ran a TM backup to an external drive. It completed. Within 5 minutes of completion, without doing very much on the Mac but read via Safari, I launched TM backup again. This time, wanted to do 12.11 GB of files! No way 12.11GB of files changed on the Mac (far as I know). Seriously messed up somewhere.

Sorry, I used the wrong term. Aren’t they file system hard links that make the unchanged files appear to be duplicated, so you can browse them? Here’s a brief explanation.

That makes sense. I know about “hard links” as I used to be a heavy user of Linux and Unix (years gone by). I didn’t know that’s how TM presents the incremental backup files. Far as I know OSX works pretty much the same. And it’s acknowledged that it’s hard to tell the difference between a hard link of a file and the file. Info in Finder doesn’t say, and i couldn’lt find a way for “ls” to do it either. Probably missed something. No matter, but, given the explanation, I’m pretty sure they are indeed hard links.

I jumped to the concluding that the GB of backup were those files. Something else.

If I don’t get anywhere, I’m going to refocus on Chronosync as I already have and use it.

My understanding is all hard links are the file (point to the same data), until all the hard links are deleted, then the file is no more.

As @JohnAtl says, a hard link is indistinguishable from the original file. This means that if you do “ls -i” on the hard link, it will list the same inode number as the original file. Also, “ls -l” will show the number of links for a given file. Finally, don’t forget directory hard links, which are unique to macOS.

I use the Time Machine Editor app to only run a Time Machine backup every three hours instead of once an hour. Now I never notice Time Machine and there is always a backup waiting for me. Backing up every hour was overkill for me and the process often couldn’t finish before it was time to start again.

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I never knew that existed - it looks promising - definitely a missing feature which Apple should have included

Apple did provide a tool to more finely control and monitor Time Machine. See the command “tmutil”. You can read details with the “man” command inside a terminal session. Complete and are their ideas of things to add? Sure. But it is there.

My hunch is that the Time machine Editor app is a “front end” to “tmutil” and gathers other system info, e.g. status of sleeping or not, and probably other clever things.

But to do a simple scheduled turn on/off of Time Machine one could run a couple of scheduled cron jobs to turn on, then three hours (or whatever) later, turn it back on.

Yes, requires knowledge of cron and tmutil, but not complicated, fully documented, and part of the Apple offering.

I’m going to let this issue of “too many files” go–accepting that’s the way it is. It could be that the file count is over-blown and is only just a count of what Time Machine is looking at vs. copying. I don’t know and from what I can tell, we’ll never know.

Thanks to all for contributions. (goign to setup a couple of strategic Chronosync scheduled tasks to add another set of belt and suspenders to my backup regime).


Good idea. In my experience, TimeMachine will fail you.


Yep. I’ve never had a Time Machine backup set that lasted more than six months before macOS declared it was corrupt and unusable. ChronoSync backups to external drives, and Backblaze and Arq --> B2 have been 100% reliable.


I have Time Machine backup and a SuperDuper bootable clone to give me peace of mind.
Whenever I want to speed up a Time Machine backup, I run the command sudo sysctl debug.lowpri_throttle_enabled=0. This lets Time Machine have the processing power it wants and makes it go faster. But be aware that this command speeds up all background processes, so you might not want to have it on all the time. Unless you like having photoanalysisID and mdworker taking over your computer. :disappointed_relieved:

I must be an exception. I’ve been using Time Machine for years and had only one corruption issue, and that was a long time ago. Of note, I’m backing up to a Time Capsule.

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In followup, with Big Sur, Time Machine is behaving much better (and acceptably) on both my iMac and MacBook, both backing up to a couple of devices including to a NAS. DIdn’t do anything beyond the upgrade. Of course that anecdotal evidence, but that’s all I got.


But that’s why we we use a Mac, isn’t it? So we don’t have to read and understand the UNIX documentation for cron and tmutil?