grub-setup: warn: Attempting to install GRUB to a partitionless disk! Will it boot?

[Netizen]

Today I saw new updates on the web interfaces however I tried to run apt-get update and then apt-get dist-upgrade from the console. It is the fist time that I was presented with a question of where to install GRUB and I had options like /dev/sda -- /boot -- /dev/sdb.

The second option (/boot) had a - next to it and I assumed that this was the correct place to place GRUB. I was however later presented with the following error:

Setting up grub-pc (1.99-27+deb7u2) ...
/usr/sbin/grub-setup: warn: Attempting to install GRUB to a partitionless disk or to a partition. This is a BAD idea..
/usr/sbin/grub-setup: warn: Embedding is not possible. GRUB can only be installed in this setup by using blocklists. However, blocklists are UNRELIABLE and their use is discouraged..
Installation finished. No error reported.
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-2.6.32-25-pve
Found initrd image: /boot/initrd.img-2.6.32-25-pve
Found linux image: /boot/vmlinuz-2.6.32-24-pve
Found initrd image: /boot/initrd.img-2.6.32-24-pve
Found linux image: /boot/vmlinuz-2.6.32-23-pve
Found initrd image: /boot/initrd.img-2.6.32-23-pve
Found linux image: /boot/vmlinuz-2.6.32-22-pve
Found initrd image: /boot/initrd.img-2.6.32-22-pve
Found linux image: /boot/vmlinuz-2.6.32-20-pve
Found initrd image: /boot/initrd.img-2.6.32-20-pve
done


1) Did I choose the correct destination for GRUB?
2) Shall I reboot the server or there is a possibility that it might not boot at all? The server is remote so I will run into problems
Please help!

 

[gkovacs]

Re: grub-setup: warn: Attempting to install GRUB to a partitionless disk! Will it boo

I have only updated grub on a virtualbox test Proxmox (not yet on the production servers), and I chose /boot. It boots fine.

 

[ebiss]

Re: grub-setup: warn: Attempting to install GRUB to a partitionless disk! Will it boo

Is it a debian update BUG ?
Confused a lot.

 

[Shazan]

Re: grub-setup: warn: Attempting to install GRUB to a partitionless disk! Will it boo

You shouldn't install GRUB on a partition, you should install it on the device/disk where the partition /boot resides (eg. /dev/sda)

 

[curlingcanteen]

Re: grub-setup: warn: Attempting to install GRUB to a partitionless disk! Will it boo

Just experienced the same problem. My choices were: /dev/sda, /dev/md0 (I think), and /dev/sda1. I looked at fdisk -l and found that /dev/sda1 was marked as bootable, so chose that for the grub install. Alas, I also got the warning message above.My server setup is hardware raid, so there is only one disk visible to the OS.

 

[mir]

Re: grub-setup: warn: Attempting to install GRUB to a partitionless disk! Will it boo

If your partition /dev/sda1 is marked as bootable then you should install grub to /dev/sda.

Explanation:
If /dev/sda1 is marked bootable and assuming your server boots then /dev/sda will be the device your BIOS is will be looking for the boot sector to redirect control to the boot strap sequence. A boot strap sequence needs to be available within the first sector of your disk which means the first 512 bytes of the disk. Grub is a boot strap sequence so your BIOS must redirect control to grub when initial testing is carried out. That's why you need to configure grub to install itself into /dev/sda which will ensure that grub is installed on the first sector of the harddisk.

 

[curlingcanteen]

Re: grub-setup: warn: Attempting to install GRUB to a partitionless disk! Will it boo

Cool, thanks for the explanation. Do you have a solution to resolve the situation we currently find ourselves in? Yes, the server still boots. But I'm guessing that now I have the original grub on sda and the updated one on sda1. Will update-grub resolve these issues?

 

[mir]

Re: grub-setup: warn: Attempting to install GRUB to a partitionless disk! Will it boo

Try grub-install --recheck /dev/sda

 

[ebiss]

Re: grub-setup: warn: Attempting to install GRUB to a partitionless disk! Will it boo

Why apt-get update make setup grub ?
Is it a bug somewhere ?

For most people it's confused .

 

[mir]

Re: grub-setup: warn: Attempting to install GRUB to a partitionless disk! Will it boo

Well, if the package containing grub is updated I would expect grub to rerun setup so that the old grub installed in the boot sector is replaced by the new grub.

 

[ebiss]

Re: grub-setup: warn: Attempting to install GRUB to a partitionless disk! Will it boo

Thanks for your info.
But use CentOS alot , "yum update" never have this kind problem.

 

[mir]

Re: grub-setup: warn: Attempting to install GRUB to a partitionless disk! Will it boo

This is not true. Yum does exactly the same if grub is updated.