[12:18] <eepy_wombat> Hello?
[17:20] <lmat> I installed xubuntu from a USB drive just now, and restarted the computer. Upon restart, it is as though there is no installation present on the drive. The computer is a mini-pc: https://www.amazon.com/dp/B0DYNPBYVL  I installed arch linux a week or so ago, and I think that was able to boot (but I don't remember if I actually got around to rebooting, or if I had just finished installing and hadn't booted 
[17:20] <lmat> into the new system yet :'(  )
[17:20] <lmat> How can I diagnose the problem and figure out what's going wrong?
[17:24] <rfm> lmat, what disk layout did you choose? You probably should have taken "erase disk and install xubuntu", if you took one of the others it may have installed alongside or on top of the arch install and made a mess
[17:27] <rfm> lmat, it might be recoverable, but it would involve booting the live usb, inspecting the partition table on the disk, mounting the xubuntu partition, chrooting into it, and running grub-install. Unless you're familiar with that kind of stuff, reinstalling would be quicker
[17:39] <lmat> rfm: I didn't choose any "install alongside". Erase and install.
[17:39] <lmat> rfm: I have installed twice now with the same effect. I am comfortable doing what you mentioned.
[17:42] <lmat> rfm: How should I mount it? I did    sudo mount /dev/sda2 /mnt;  and I now see  /mnt/boot has lots of stuff in it. Where should /dev/sda1 be mounted? (/dev/sda1 has /EFI/BOOT and /EFI/ubuntu in it)
[17:43] <lmat> nevermind, it's in /etc/fstab. Now how should I chroot?
[17:45] <lmat> I can just   sudo chroot /mnt;  but is that good enough? in boot/efi/EFI/ubuntu/, I see a three-line grub.cfg. Does that indicate that grub was properly installed?
[17:46] <lmat> also  grep -r boot/efi/EFI vmli;  returns nothing. I think vmlinuz should be in there somewhere to indicate booting of the kernel? Or is that chained somehow?
[17:47] <rfm> lmat, there are some instructions in https://help.ubuntu.com/community/Grub2/Installing 
[17:50] <lmat> inside the chroot, sudo grub-install --target=i386-pc /dev/sda; fails with  "grub-install: error: /usr/lib/grub/i386-pc/modinfo.sh doesn't exist. Please specify --target or --directory."
[17:53] <rfm> lmat, oh I guess those instructions are pretty old. ubuntu hasn't supported i386 (32 bit) for years
[17:54] <lmat> maybe --target=x86_64-efi is better
[17:54] <rfm> first thing I'd try
[17:56] <lmat> grub-install --target=x86_64-efi --efi-directory=/boot/efi/ --bootloader-id=GRUB; inside the chroot fails with, "grub-install: error: cannot find a device for /boot/efi/ (is /dev mounted?)." and  grub-install --target=x86_64-efi --efi-directory=/mnt/boot/efi/ --bootloader-id=GRUB;  outside chroot says, "grub-install: error: disk `hostdisk//dev/sda1' not found."
[18:00] <rfm> oh, you need the bind mounts. I am failing to get google to pop up an example
[18:04] <rfm> lmat, https://forums.linuxmint.com/viewtopic.php?t=320504  has something that looks right to me, search down to "For UEFI"
[18:05] <rfm> lmat, I don't see any point for cp /etc/resolv.conf though
[18:07] <rfm> lmat, ah https://forum.level1techs.com/t/reinstall-grub/134056 looks cleaner (again search down to "For UEFI", and you probably want the --target on the grub-install)
[18:13] <lmat> rfm: Okay, thank you! I need to step away, but I'll come back and let you know how it goes!
[18:39] <xu-help87w> torrent tutorial
[20:17] <lmat> I got a great error this time: "grub-install: warning: EFI variables cannot be set on this system."  That suggests the system wasn't started in UEFI mode I think...
[20:24] <rfm> lmat, I forgot to tell you to expect that grub-install would fail, since the installer would have tried, but this way we at least get a message.  
[20:25] <lmat> I also mounted the efivars (https://unix.stackexchange.com/a/418913) and now grub install says "Installation finished. No error reported."
[20:26] <rfm> lmat, probably the problem is the UEFI firmware on this thing is just buggy.  You might look for a BIOS update on the mfr's site (if there is one!) but more likely just go into the setup dialog and set the boot device through the menus there
[20:27] <rfm> Or maybe getting the efivars set up fixed it!
[20:27] <lmat> yes, certainly could be a buggy uefi. I checked the setup dialog and it looks good: it is set to boot to the hard drive. Yes, perhaps this round of setting EFI vars is good. I'll reboot, and if it doesn't work properly, have a look through the BIOS setup.
[20:32] <lmat> rfm: I checked BIOS boot devices and changed the first item, "NVME", to "ubuntu..." Now it works. Thanks for the links and helping me through!
[20:55] <rfm> Great, don't know why the installer didn't get it right, it usually does.