Update from MacOS 14.3 to 14.4 does not start after update loaded on iMac 2019 Intel

There are factors:

1 - Like poor Wifi connection

2 - Slow wifi connection

3 - Too many other people downloading at the same time and Apple Severs are overloaded

4 - Software on the computer interfering with the download process including AntiVirus Software

Notation: Disabling the AV Software may or may not solve the issue. Removal of the AV Software may increase the chances of the download to perform as expected.

5 - Running behind a VPN which may increase Packet losses or corruption of the download

6 - If via wifi too many Other devices using the wifi at the same time reducing the Bandwidth to your computer.

7 - Best Results are via Ethernet Cable to Router

8 - Restart in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts. The boot up will be slow and can take some time - Normal and Try Again using the Software Update Applet in System Preferences

9 - Worst case - Restart in Recovery Mode and choose Reinstall macOS. This in theory will pull the latest version of Sonoma available and commence the installation.

No I am Not an AI / ChatBot

Wolfgang1955XY wrote:

When I start the update from the system preferences then the update is downloaded what takes around 18 minutes. Then it seems that the installation is started with the messages "macOS Sonoma 14.4 vorbereiten" and "noch ungefähr 30 Minuten" and the progress bar somewhere in the middle. But after the time of more than 30 minutes the messages and the progress bar are still the same.

The activity monitor shows the process com.apple.MobileSoftwareUpdate.UpdateBrainService that takes 20 to 30 percent of CPU and never stops. When I kill the process (recommended solution) the software update fails.

I have found a log file MobileSoftwareUpdate/restore.log where the following sequence occurs 16 times:

CleanupPreparePath main() started

setSystemTargetUUID will use / as the target

Found update container: LPAPFSContainer: AppleAPFSMedia, UUID: A2FEC6B7-7C15-40B9-8B04-AE8CD30A9117

Found update volume: LPAPFSVolume: Update, Mount: /System/Volumes/Update

Will open restore file at: /System/Volumes/Update/restore.log

A similar problem occured already in 2020 on Intel Macs. It seems that the problem is only on Intel Macs.

I have no software installed that would influence the system and I have disabled all background processes in the system preferences.

I recently updated two 2019 MacBook Pros (Intel). One was on 14.2, the other on 14.3. Both of these were brought up to 14.4, and that update took a fairly long time. It indicated "30 minutes" for "preparing" and was there for a lot more than 30 minutes. But after a very long time on that stage, the rest of the "preparing" went much faster than shown. I also recall one near final step on "5 minutes" for a LOT LONGER than 5 minutes. What I am suggesting is to leave it alone and not interfere. My lesson learned is that "a watched update never finishes" (a corollary is "a watched Time Machine backup never completes"). By killing the process that was installing the update (not something I have ever done nor would I recommend it), you may have left your Mac in an indeterminate condition with respect to trying the update again. I have never been in such a situation but I think the advice from PRP makes a lot of sense to me, especially steps 8 and 9.

Wolfgang1955XY wrote:

A solution would be to dowmload the incremental update as dmg or installer file, but I cannot find such a file any where. All sources of updates to Sonoma 14.4 on the internet offer always the full installer, that means I would have to install a complete macOS if I only need the changes from 14.3 to 14.4. Some years ago Apple offered always the incremental installers, so I would like to know if they are available somewhere for Sonoma.

Apple creased to offer Incremental updates sine macOS 10.15 Catalina

Plus, incremental updates ceased being offered in .dmg format since about OS X 10.12 Sierra

This this issue some how related to your other similar issue ( Continuity purposes )

Launch time of Sonoma is 4 minutes on iMa… - Apple Community

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