Help with Windows 10 iot 1809 slow boot

Hi all.

I work for a small ship simulation company, and we use small touch screen computers (1GHz Atom CPU & 4GB RAM).
Since they are never supposed to have internet, we use Windows 10 IoT (currently still on Win10 1809) since we then don't need to activate Windows.
We make images for these using a virtual machine, which we regularly update with windows updates and other improvements, and then do a sysprep on before taking a new image.

The issue is that the boot time seems to increase with each image we take.
Using the first image that was made after a clean install (v2.1.1), it takes around 35 seconds from after post until I see the desktop.
But on the newest version (2.13) it now takes 3 minutes and 40 seconds.

The degradation is not sudden, but it seems to get worse and worse after each new image.

I'm trying to figure this out, but slowly going insane in the process. Although I've done recordings of the boot with windows performance recorder, I don't know how to properly interpret the results.
Is there anyone who could help me figure this out?

ETL file from early image with normal boot time:
CP10 Image-v2.1.1.Boot_1.etl - Google Drive

ETL file from latest image with slow boot:
CP10 Image-v2.13.Boot_1.etl - Google Drive

If I've recorded these files with the wrong parameters, I can quickly record new ones if needed.

dalchina said:

- curious?

Member @zinou is best placed to advise on using the WPA.
You can find example threads on tenforums too.

The no activation comment was aimed at it being Windows IoT.

You could try to disable write caching.

Dev.Manager-->rightclick the Drive-->Properties-->Policies

It may help for quicker boot.

NTN said:

You could try to disable write caching.

Dev.Manager-->rightclick the Drive-->Properties-->Policies

It may help for quicker boot.

Thanks for the suggestion.
It shaved about 10 seconds off the boot time.
However, the first image version has write caching enabled, so although it helps, it can't be the root cause of the increased boot time.

I do not know if this will work, but I read:

"So the one thing we can do for IoT Core is to enable UWF. The concept of the write filter goesall the way back to Windows NT Embedded. The idea is that the filter protects the OS partition by directing all writes to an overlay. The overlay could be RAM or diskcache implementation. The Enhanced Write Filter and File Based Write Filter were introduced in XP Embedded and carried on in Windows Embedded Standard 7. Starting with Windows Embedded 8 Standard, UWF was introducedas the future replacement for these filters, and is the only filter available in Windows 10.
We custom built images for all three platforms with the UWF filter installed (IOT_UNIFIED_WRITE_FILTER). We enabled the filter to protect C: drive, RAM overlay, and no exclusions. The same boot media for the initial sudden power-off test was usedagain. The power was pulled three times oneach system. All three systemswere able to boot again without any trouble.The combination of NTFS and UWF performed as expected,protecting the system from sudden power loss.Microsoft made a wise choice to make UWF available for IoT Core."

Installing UWF
https://learn.microsoft.com/en-us/wi.../uwf-turnonuwf

Megahertz said:

Please edit your profile with ALL your hardware specs. It will help us to help you
System Specs - Fill in at Ten Forums

Try to disable fast start

Hi,
Sorry that it wasn't added before. Added now.

Fast start is already off (causes other issues when enabled)

- - - Updated - - -

zinou said:

Hi,
I don't see any boot delay in the traces you captured !

Hmm.. but there is a clear difference in the times in the captures. One is 189 seconds, and the other is 269 seconds.
That does not match with the 3 min difference, but at least one shows longer boot than the other.
Is there something I can add to the trace options to give a better trace?