Try this: https://github.com/pikvm/pikvm/blob/master/pages/cookbook.md#create-a-microsoft-windows-based-flash-disk-image

Thanks for quick response, tried several Linux ISOs:
Ubuntu-budgie-21.04 not booting, not even showing up in the boot menu.
Tiny Core Linux x64 (12) boots normally.
Very strange behavior
Can it be related to the fact that pikvm truncates files larger than 2.2GB?
Currently trying to upload ubuntu image via web interface to see if it will boot.

Yes

Both linux and windows?
So how do you handle it?

Large images cannot be booted when emulating a CDROM. It doesn't matter Linux or Windows.

Tried uploading iso images via web interface - still didn't work, but I certainly remember booting large isos with pikvm (strelec iso).
How come?

So uploading or booting doesn't work?

No, tried both Linux (ubuntu) and WinPE (strelec).
Windows gives 0xc000000d error, Linux doesn't show up in the bios boot menu at all. (same as copying to microSD directly).
That drives the whole ISO boot mechanism useless since you don't have modern bootable ISOs under 2.2 GB.
Please check for regression in the newest versions of pikvm.
Thanks!

Nothing has changed in this place. ISO never working with images over 2.2 GB. Big images require flash drive emulation

Ok, it is what it is then.
Can you please add flash image creation in the web interface and enable option for read write the image partition?
So one can create, map and write to flash drive emulation without leaving the web interface?
Would be a killer feature!
Thanks

I'd rather do DVD support in the future

Rather one would be great!

DVD emulation would probably solve this issue, most ISO are DVD sized these days for system with fancy GUI.

Yes but the correct DVD emulation is not, this is on the todo list but no ETA as other things are taking more priority.

Actually I solved that 2 years ago... that size is hard-coded in OTG mass storage.. Do not know if you will increase this limit (or even disable that check) if that simply start to work.. That time I did not test recompile my own kernel module with such "fix"

https://github.com/torvalds/linux/blob/master/drivers/usb/gadget/function/storage_common.c#L247

It's not so easy:

• https://lkml.org/lkml/2015/3/7/388
• https://linuxehacking.blogspot.com/2013/07/how-to-emulatore-dvd-rom-hardware-usb.html
• https://www.spinics.net/lists/linux-usb/msg198041.html

Fresh related and not accepted patches:

• https://www.spinics.net/lists/linux-usb/msg214025.html
• https://www.spinics.net/lists/linux-usb/msg214026.html
• https://www.spinics.net/lists/linux-usb/msg214027.html (looks wrong)
• https://www.spinics.net/lists/linux-usb/msg214028.html
• https://www.spinics.net/lists/linux-usb/msg214030.html
• https://www.spinics.net/lists/linux-usb/msg214029.html

assuming that the 2.1gb ISO patches are applied here, you can solve this Windows ISO issues by just converting the ISO extension from UDF to Joliet. Most Windows 10 and 11 ISOs have install.wim files larger than 4GB so you need to split that wim file into smaller parts. After that it all works just fine.

Tested this on drivedroid app for android and also a distribution image of gadget_cdrom for raspberry pi zero.

Still, we need a proper DVD ROM emulation for this to properly work, so far, all kernel patches for DVD ROM emulation are rejected so were still stuck with CDROM emulation at this age. Even making the UDF extension through CDROM emulation to work properly on usb gadget is pia.

There are not applied

Any idea if DVD emulation will be on roadmap anytime in 2022?

@TheLinuxGuy I don't know, sorry. Maybe I'll do it myself or try to find someone who will do it.

Workaround:

• Use Rufus or a similar ISO to flash conversion tool to write ISO to USB flash
• Use DD tool to create image from USB flash
• Upload DD image and use it as Flash mount in PiKVM

Just wanted to swing by with my annual anniversary comment asking if this feature could be prioritized in order to improve UX and convenience to all pikvm users.

Most common major linux distros which offer livecd booting bundle it on their DVD image. Example: all manjaro downloads are greater than 3GB single .iso images: https://manjaro.org/download/ -- flash mode doesn't work for them.

All workarounds are inconvenient and require many steps to make it work. If there was maybe a batch script "tool" provided by pikvm that does the automatic conversion to workaround this bug/FR then I would be happy with that if it was available and pivkm took care of it mostly for me.

@mdevaev RFC - How about shipping a pre-build image of a ventoy USB (which is about 22M compressed) with PiKVM as a 95% workaround feature? It would mean that we only would have to script putting the iso/image onto the data partition of the USB image as well. For most systems and cases Ventoy works pretty much out of the box, IMHO this would be the next-best solution besides a real DVD emulation. It would be way easier/faster, than dealing the conversion on your PC all the time, and you'd be able to download the iso's directly from the source via your PiKVM (avoiding having to down- and upload it on your local host).

As a MVP, this would be a simple "convert" button, that would:

• Set MSD to RW and unzip the pre-build ventoy.img.gz to e.g. <iso/img-name>_ventoy.img
• Expand the new ventoy-image (sparse-resize), and the data partition to the required size (with parted), to fit the iso/img to be "converted"
• Mount the data partition via loopback, copy original iso/img to it
• Unmount and set MSD to RO
  Since step 3 is limited by the speed of your storage device, ideally we would also support direct download of an image "into" a new ventoy-image. One might consider to also just have one ventoy image, and load all images into there (since Ventoy is multi-boot out of the box).

I'd happily support the implementation of such feature.

@folfy I'm not sure. It looks like a crutch instead of fixing a DVD in the kernel.

@mdevaev I get that, but I doubt fixing DVD device emulation is gonna be an "easy" task to solve in the near future?
Actually, if the solution didn't get ya sold, what if I could implement it in a way that you could just on-demand mount a Ventoy-image with the existing MSD partiton as one virtual storage, allowing you to select and boot any image via Ventoy? It actually might be viable too, and this overall would be useful even if we would have a working DVD emulation, I mean Ventoy has more features.

Any solution made now will have to be supported, so I wouldn't want to do any special magic. in fact we'll probably make a dvd next year.

Is it possible to know when this would be a thing? Perhaps a rough estimate?

I'm not working on it right now because there are higher priorities. You can use Ventoy as a workaround.

Sorry to dogpile, but ran into this and was a bit disappointed.

However, creating an img file, mounting that as writeable, and using the Windows Media creation tool on the resulting USB flash drive image boots for me, in uefi mode without CSM enabled. Don't even need to use ventoy.

Count me as disappointed.
I need to be able to install DVD images to install OSes like ubuntu.

You can use Ventoy to boot DVD images.

Ventoy is paid for PXE. ventoy/PXE#51 (comment)

for images like ubuntu you can emulate DISC instead DVD, because that ISO is hybrid, so it should work same as USB flash.