Bootloader can't be installed with multiple HDDs

[Rick Kerkhof]

I have a system with multiple HDDs. It tries to install the bootloader on /dev/sda, but first of all it needs to go on /dev/sdb. So, installer crashes, everyone happy.

When I attempt to manually install GRUB on /dev/sdb, I get the following error:

ubuntu@ubuntu:~$ sudo grub-install /dev/sdb
Path `/boot/grub' is not readable by GRUB on boot. Installation is impossible. Aborting.

Installation on this system went well except for that bit.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: ubiquity 2.14.6
ProcVersionSignature: Ubuntu 3.8.0-19.29-generic 3.8.8
Uname: Linux 3.8.0-19-generic x86_64
ApportVersion: 2.9.2-0ubuntu8
Architecture: amd64
CasperVersion: 1.331
Date: Tue Jul 23 12:25:25 2013
InstallCmdLine: initrd=/ubninit file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash -- BOOT_IMAGE=/ubnkern
LiveMediaBuild: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130424)
MarkForUpload: True
ProcEnviron:
 TERM=unknown
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)