Level 1

23 points

High CPU usage by diskimagesiod during Time Machine backups on 2021 5K iMac

202 5K iMac running Sequoia 15.0

Since upgrading when diskimagesiod is running it is absolutely HAMMERING the CPU. Currently backing up and fluctuating between 160-515%.

Fans are running full blast and the machine is hot.

I've tried a new Time Machine backup but same. This is to a Synology NAS that I've been using for year or so, other machines backing up to it using TM are fine.

It's not just the first backup hammering things, it's all subsequent backups.

Is this a known issue?

[Re-Titled by Moderator]

iMac (2017 – 2020)

Posted on Sep 25, 2024 6:08 AM

Top-ranking reply

BDAqua

Level 10

250,259 points

Posted on Oct 12, 2024 9:35 AM

In Disk Utility>View, select Show all Devices, highlight the top left entry.

Run Disk First Aid on all items in the left panel, from top down.

Are you running any VPN, Anti-Virus, or Cleaning apps?

Eject your TM drive for a test.

View in context

23 replies

Oct 12, 2024 8:29 AM in response to eludlow9876

I have the same problem on a Mac Book Air M1.

Timemachine is on Synology.

I tried deleting the backup and creating a new one. It didn't help

BDAqua

Level 10

250,259 points

Oct 14, 2024 10:40 AM in response to vojtech257

Good to hear my friend.:)

Nov 1, 2024 10:17 AM in response to eludlow9876

I have firewall disabled since 15.0 (it was broken, kept disconnecting ssh connections) - but diskimagesiod still maxes out my CPU and makes machine very unresponsive during TM backups.

Nov 1, 2024 9:25 PM in response to eludlow9876

So far no advice has helped. Not even the latest MacOS update.

The time machine is unusable in this state. I was forced to turn it off and am looking for a replacement.

BDAqua

Level 10

250,259 points

Nov 20, 2024 10:37 PM in response to dbalogh

👍

eludlow9876 Author

Level 1

23 points

Dec 4, 2024 10:13 AM in response to BDAqua

Firewall not even turned on here so can't disable it.

Absolutely maddening to be able to use Time Machine suddenly.

JALx69

Level 1

4 points

Jan 13, 2025 4:48 AM in response to eludlow9876

Same problem for me on M4 Mac Mini on MacOS 15.2. Incredibly disruptive when working on the device. Luckily I have Windows 11 as a backup desktop.

xMirek

Level 1

4 points

Jan 15, 2025 11:45 PM in response to eludlow9876

M1 Pro, 16GB Ram. In this state even Preview of 1.4MB jpeg takes about 5 sec. Not mentioning regular work.

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High CPU usage by diskimagesiod during Time Machine backups on 2021 5K iMac