Grub rescue prompt upon reboot

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scurrier

Active Member
Sep 9, 2017
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Hello,

Today I rebooted my Proxmox 7 Proxmox VE 8.2.7 server and was greeted with the grub rescue prompt. I have (had?) a 2-disk ZFS mirror configuration, but now it's not booting. I am not experienced with troubleshooting boot issues with ZFS. What should I do?

The screenshot shows the commands I've run so far to look ways to boot. Not sure if that is useful or not.

This failure kills me because I was waiting for TrueNAS Scale to go stable so I could set up a Proxmox Backup Server on a fresh VM on it rather than having to migrate. Foolish.

1745894596723.png
 
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I tried booting to the Proxmox VE 7.4 iso and found the Rescue Boot option. No success though, it's giving this error:
1745899933467.png
 
Sorry, @Kingneutron, I tried zfsbootmenu's recovery image and I don't get it. I formatted a USB stick as FAT32 and dropped the EFI file in EFI/boot/Bootx64.efi, then ran that several different ways via my motherboard's boot menu. Best I can get is that it seems to run the efi file, but ultimately says "Failed to find bootable partition." I'm not sure if that's coming from zfsbootmenu or UEFI. Not sure what to expect from zfsbootmenu.
 
I also tried the non-recovery image of zfsbootmenu, but to the same effect. I might be making my USB stick wrong. I give up for today.
 
issues like this are the reason PVE switched away from letting Grub boot directly from ZFS.. if you have an ESP on your disk(s) that is big enough, you can initialize it using "proxmox-boot-tool" (after booting a live CD and chrooting into the PVE rootfs). if you don't, you might need to use some non-ZFS disk (or an USB drive) to store the ESP?
 
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fabian said:
issues like this are the reason PVE switched away from letting Grub boot directly from ZFS.. if you have an ESP on your disk(s) that is big enough, you can initialize it using "proxmox-boot-tool" (after booting a live CD and chrooting into the PVE rootfs). if you don't, you might need to use some non-ZFS disk (or an USB drive) to store the ESP?
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Thanks. I will try that after work today. Is it clear what the problem is? I assumed disk failure but maybe not since theses were mirrored and known healthy as of a few weeks ago.

Looks like maybe the "proxmox-boot-tool refresh" command is what I need.
 
To get an idea of what kind of partitions I'm dealing with according to @fabian's comment, I booted a live Debian from USB and ran lsblk:
1745977897910.png

sda and sdb are my mirrored ZFS disks. sdc is the USB disk.

...from the partitions listed, I conclude that I do not have a big enough ESP for the proxmox-boot-tool @fabian mentioned - agree?

Is the problem clear at this point? What should I do next? Somehow I need to "initialize" it using an ESP on some other disk?

Thanks in advance.
 
yeah, there isn't really space for an ESP there.. you could put the ESP on a third drive if you have a free slot, or an USB drive otherwise..
 
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