Re: Hurd rumpdisk on real hardware

Hi João,

On 18/09/2025 09:58, João Pedro Malhado wrote:
> I read the other thread, but I'm unsure about the hypothesis that these errors
> are related to the low amount of RAM. On my Toshiba netbook where rumpdisk is
> failing with similar errors to what you are seeing, I indeed also have 1Gb of
> RAM. But on my HP laptop where rumpdisk works fine I have 512Mb.
> If this is memory related, there must be something weird going on with RAM
> segmentation. I'm attaching gnumach's dmesg in case anyone is able to make sense
> of it.

It is true also that Hurd/Rumpdisk boots succesfully on a 512MB Qemu 
virtual machine. The reason it works is that total memory is so low that 
there is no HIGHMEM memory segment at all. All memory except the small 
DMA total is allocated to the DIRECTMAP segment and there is sufficient 
in that one segment to support the initial boot and to permit sufficient 
spare to permit pageout to operate successfully. Your log shows only DMA 
and HIGHMEM segments only as well so it should operate as per my Qemu test.

All the best,

Mike.