Installation on Legacy BIOS, wont boot.

[christopher_g]

Hello everyone,

I'm a new proxmox user/installer. I'm trying to install it on an older AMD64 machine that does not have SecureBoot/Fastboot/UEFI options in the BIOS. The installation finishes successfully and reboots but it fails to boot after that. I checked and double-checked the boot order and disabled everything but the HDD.
If I use the ISO to boot into Rescue Boot, it indeed comes up. I check /dev/sda1 and the BIOS boot partition is there. I tried reinstalling grub to /dev/sda1 and it completed but didn't help.

Any suggestions or actions I can take to get my old BIOS to recognize the partition?

 

[leesteken]

Last time I installed Proxmox on an old system, I installed it on top of Debian but using that work-around might be a bit overkill as your system appears to be almost working.
Maybe the installer created a GPT instead of a MBR? What are the (whole) outputs of fdisk -l /dev/sda and gdisk -l /dev/sda?

 

[christopher_g]

root@pve:~# fdisk -l /dev/sda
Disk /dev/sda: 238.47 GiB, 256060514304 bytes, 500118192 sectors
Disk model: SAMSUNG MZ7TY256
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 14E75C33-7CC7-4756-AE96-9CCB794859C2

Device       Start       End   Sectors  Size Type
/dev/sda1       34      2047      2014 1007K BIOS boot
/dev/sda2     2048   1050623   1048576  512M EFI System
/dev/sda3  1050624 500118158 499067535  238G Linux LVM
root@pve:~# gdisk -l /dev/sda
GPT fdisk (gdisk) version 1.0.6

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.
Disk /dev/sda: 500118192 sectors, 238.5 GiB
Model: SAMSUNG MZ7TY256
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): 14E75C33-7CC7-4756-AE96-9CCB794859C2
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 500118158
Partitions will be aligned on 2-sector boundaries
Total free space is 0 sectors (0 bytes)

Number  Start (sector)    End (sector)  Size       Code  Name
   1              34            2047   1007.0 KiB  EF02 
   2            2048         1050623   512.0 MiB   EF00 
   3         1050624       500118158   238.0 GiB   8E00 
root@pve:~#

I had Debian on this system prior and yes, it worked with grub without issue.

 

[leesteken]

According to the gp output your partition table if of the GPT type and your (old) system can probably only start from a MBR. Maybe this is a bug in the Proxmox installer but maybe it cannot detect whether the system is to old to boot from GPT.

I think it is possible to convert a GPT to MBR by running gdisk /dev/sda and type r to go into the recovery and transformation options (experts only) and then press g to convert GPT into MBR and exit. I have not done this before and it may mess things up completely or simply not work, but I think it is your best shot to make the system bootable.

Maybe someone else here know a better way or has more experience with this?

EDIT: I don't really understand why the system won't boot from the protective MBR, but I still think that a GPT won't work on an old system. Maybe a BIOS update can help? But there probably isn't a very recent one.

 

[christopher_g]

According to the gp output your partition table if of the GPT type and your (old) system can probably only start from a MBR. Maybe this is a bug in the Proxmox installer but maybe it cannot detect whether the system is to old to boot from GPT.

I think it is possible to convert a GPT to MBR by running gdisk /dev/sda and type r to go into the recovery and transformation options (experts only) and then press g to convert GPT into MBR and exit. I have not done this before and it may mess things up completely or simply not work, but I think it is your best shot to make the system bootable.

Maybe someone else here know a better way or has more experience with this?

EDIT: I don't really understand why the system won't boot from the protective MBR, but I still think that a GPT won't work on an old system. Maybe a BIOS update can help? But there probably isn't a very recent one.

Running the above at least booted me to grub_rescue, lol.

The BIOS is the latest possible version, I verified that.

 

[leesteken]

Running the above at least booted me to grub_rescue, lol.

Sounds like the system is now able to boot from the drive. Maybe a guide for repairing GRUB can help you further? There are may ways (and examples on the internet and probably in this very forum) to boot from a LiveCD or the Proxmox installer and chroot into the system on the drive to re-ruin grub-install.

 

[christopher_g]

I think I fixed it?

I get a screen saying Volume group "pve" not found.
Happen to know what that is? After that -- it flashes and goes to my pve login.

Okay so for anyone else having this issue, boot into Rescue Boot or someother method to get at /dev/sda.
I deleted /dev/sda1, and /dev/sda2 using gdisk.
Following this, I created a partition from 2048 that is 512MB in size.
Convert everything using gdisk r, gdisk g, gdisk w.
Run: grub-install /dev/sda
Reboot.

Many thanks for leading me in the right direction.

 

[christopher_g]

Added rootdelay=2 to /boot/grub/grub.cfg seems to have fixed the Volume group "pve" not found issue.

I might be all set for now, thanks.

 

[leesteken]

Glad you got it to work and thanks for reporting back on how you did it.