Time Machine Backup suddenly stops working correctly

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Level 1

31 points

Time Machine Backup suddenly stops working correctly

Hi guys!

I've been having problems with my Time Capsule for a few months now but I haven't been paying much attention until now. I want to upgrade to Big Sur from Mojave and want to make sure I have one clean backup before I do.

Up until now, I had notifications that Time Machine backups could not be completed on a random basis but it continued nevertheless once in a while.

Last week though, I started having messages giving me two options : either being reminded later of that same message, or delete all my backups and creating new ones now. After a few days of hesitation, I decided to start from scratch and select the second option. However, after it completed, it wouldn't go through one backup, stating "Waiting for first backup to complete" and only performing up to 1 Gb of backup (out of 1000 Gb).

I tried to erase the disk with zeroes, remove the drive from Time Machine and doing it all over again but so far, no luck :/

Here is the log for my last backups over roughly 30 minutes, it seems there is an error on my Mac at the adress file:/// where operations are not permitted, another error where some addresses are not browsable and an error with the indexer not being available, preventing the backup to go through?

Thank you so much in advance,

Kindest,

Charles

Mac Pro, macOS 10.14

Posted on Nov 30, 2020 12:59 AM

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Answer 1

Top-ranking reply

N3M1C0 Author

Level 1

31 points

Dec 1, 2020 1:41 AM in response to BDAqua

Yes, it's really unstable, I had to load the attachments 5-10 times before it actually loaded :)

I did run Disk First Aid on both internal and Time Capsule drives, and both returned no errors.

But I have good news this morning!

After a bit more reading online, I learned that macOS Sierra and up have trouble backing up large volumes of data when free disk space is low, reportedly because of APFS and new snapshots management methods. So I managed to free an extra 10 Gb of data to have 36 Gb of free disk space, then Time Machine backups resumed. It took it several tries (100 Gb, then 300 Gb, then 600 Gb, then 500 Mb), although each new try started immediately when the previous one ended (instead of waiting for the next backup, as if Time Machine just needed to take breaks once in a while) and it just completed its first backup as I write this post!

So, to recap:

Backups were first failing because of one file (that file was inside the Contents folder of Maxxon's Cinema4D installer app, that app is provided in 'Library' through the installation of Adobe After Effects), this was clearly displayed in the logs so if others have this kind of issue, look for this kind of message:

Error: (-36) SrcErr:YES Copying /Volumes/com.apple.TimeMachine.localsnapshots/Backups.backupdb/Mac Pro de Charles/2020-11-30-090959/Macintosh HD/Library/Application Support/Adobe/Keyfiles/AfterEffects/17/CustomHooks/Maxon Cinema 4D Full Installer.app/Contents/Resources/installbuilder to (null)

I deleted the installer app (because I have no interest in Cinema4D)
Backups resumed but ultimately failed around 45-50 Gb of data
I managed to have 35+ Gb of free disk space on the internal drive (up to 25 Gb originally)
Backups resumed, backing up the entirety of my internal drive, a few Gb at a time, with no manual action to immediately relaunch the backups
After 4 backup sessions, Time Machine completed its first backup of 1Tb of data over the course of one night (18:00 > 10:00 D+1) through Ethernet connection

So if you have this kind of issue, check your logs for corrupted files or files that are impossible to copy, decide what to do with it (delete it or move it to a non-backed up location), and if backups still fail, make sure you have at least 35 Gb of free disk space for each Tb of data you want to backup.

Thanks again to the Apple Community for providing clues and helping solve problems :)

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Answer 2

N3M1C0 Author

Level 1

31 points

Nov 30, 2020 3:49 AM in response to N3M1C0

Tima Machine Backup New Log

So after a bit of reading, I saw that a file in an app that I wasn't using in an unexplored Adobe folder was maybe causing the issue, I deleted it, reformatted the Time Capsule and set up Time Machine again, it went up to 48,72 Gb of data before failing as before.

But this time, Terminal gave me no clue as to which other file was causing the process to fail, any ideas?

Thanks again,

Charles

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