I’ve upgraded my 12-year-old NAS from D-Link DNS320 with Synology DS920+ after it’s showing its age, especially with poor read/write speed, and also it’s missing a lot of modern protocols like NFS v4.1 et cetera.
Then I took this chance to configure Apple Timemachine to backup all my Macbooks. My Macbook Air’s backup worked flawlessly, but my work Macbook Pro seems to have a performance issue. The system performance will degrade, and the OS will freeze intermittently whenever the Timemachine backup runs. So I had to turn off automatic Timemachine backup during office hours, do all the tasks and restart the backup after I logged out from work.
I’ve been pulling hairs for days, and neither Apple Support nor Google is helpful at least to pinpoint me to resolve the problem. macOS Activity Monitor didn’t show any clue as my CPU utilization is >90% idle. I went as far as resetting my NVRAM/PRAM twice, but it didn’t fix the problem.
Then, I realized that I have ESET Endpoint Antivirus installed by my workplace’s MDM, and it has a “Real-Time File System Protection”. As expected, disabling the real-time protection resolved this issue. My MBP now behaves normally during the Timemachine backup.
Disabling real-time protection every time the automatic Timemachine backup is far from ideal, thankfully ESET has a feature to exclude file paths from being scanned.
In my case, I’m using NAS. Therefore you will need to exclude this path and restart the backup again.
If you have an antivirus other than ESET, you may want to explore the same resolution step with your antivirus product.