Hetzner - Setting Additional SSD as Boot


#1

Hey!

I just had an SSD installed alongside the pre-existing hard drives within my Hetzner server. Ideally, I would like to put the two HDDs into RAID 0 for storage (the data is unimportant) and then have the SSD as the boot drive outside of the RAID array.

I’m able to install an OS onto the SSD (/dev/sdc) via Hetzner’s installimage script (I comment out the two hard drives and disable software RAID), but then the server refuses to boot. I’m sure it’s something simple, but I just can’t figure it out.


#2

my guess would be that commenting out the HDDs makes installimage ignore them completly so that there is no grub (or whatever) is installed into the MBR of /dev/sda - hence you can’t boot up your OS.

I’d go into rescue mode and rewrite that MBR with grub-install (mount your root drive, chroot into it, etc.)

maybe as an alternative instead of commenting out sda/sdb in installimage you could configure them there already. you should be able to put your root onto sdc anyway.

I do have a server with additional SSDs as well but luckily they appear as sda and sdb - so no fancy stuff needed at all :wink:


#3

I’ve also seen the need on some servers to enter BIOS and change the order of the disks there.
Can’t remember where it was but BIOS only had the first two disks visible and I had to swap one for the third disk.

Then it could boot and install on that disk. OS found all disks after the boot.


#4

Thanks for the help over Skype @Falzo :blush:


#5

you’re very welcome!

for those interested, installing grub as proposed did the trick, it just came with the hurdle that those 3TB HDDs need GPT and therefore you have to have a small BIOS BOOT partition where grub can embed itself…

@mikho is also right, changing the disk/boot order in bios would be an option. sadly with hetzner you have no easy way to achieve that, as they have no ipmi, need to ask for a lara kvm etc.


#6

From my experience with the above, just dropping a support ticket they will go and make the change for you to save going through the full KVM proccess. But the GRUB work around also works!


#7

Hetzner never gave me any hard times when asking for a KVM.
Often get one within 1-2 hours and then you can have as much fun as you like.

just remember the default settings so you can revert any changes if it doesn’t boot :wink: