On Sat, Nov 30, 2019 at 1:12 AM Goffredo Baroncelli <kreijack@xxxxxxxxx> wrote: > > On 29/11/2019 22.17, Chris Murphy wrote: > > On Fri, Nov 29, 2019 at 12:54 PM Goffredo Baroncelli <kreijack@xxxxxxxxx> wrote: > >> Could you be so kindly to share the picture of the loading of the kernel/initramdisk ? Something like: > >> > >> grub> set debug=all > >> grub> initrd /boot/initrd.... > >> > >> I hope that the errors come quickly. I don't think that we need the pictuers of all the download. It would be sufficient the pictures until the first (or better second) error.... > > > > I paged through it for minutes, hundreds of pages and never found any > > errors. But these are the first pages. This might actually be some > > kind of search, not load of the kernel, because I pressed tab to > > autocomplete. But it didn't autocomplete it immediately started > > spitting out debug pages. > > > > https://photos.app.goo.gl/kpa7dJ9spAy29yj26 > > > > Is it possible to redirect grub debug output to a FAT file? > > It is possible to redirect to a serial console .. > Did the machine has a serial port ? USB and wired ethernet. So far I'm unable to reproduce in a VM with 2 partitions used for 2 device Btrfs. It might be a multi-layer bug where the 1st bug must happen before the 2nd one has a chance of being revealed. The 1st bug being the issue of phantom devices, which *are* present when the Btrfs is a single device volume, but none of the errors show up in the GRUB/pre-boot environment until the 2nd device was added (and new kernel installed). It's too bad GRUB doesn't have a debug option to write a file to a FAT file system. The btrfs debug output is extremely long. -- Chris Murphy
