grub-installer fails if root is on 27th disk

Binary package hint: debian-installer

I tried installing ubuntu-server 11.04 on a real system with 28 disks, where the disk I wanted to use as the root partition happened to be enumerated as /dev/sdaa (notice the two "a"s -- /dev/sda through /dev/sdaz are used, and then /dev/sdaa is the next disk). The installer made it most of the way through, but the grub-installer step failed.

I tried this in a virtual environment (for easier reproduction), and did:

    for i in $(seq -f'%02.0f' 28); do qemu-img create -f qcow2 d$i 4g; done

to make 28 virtual drives (the qcow2 format means this uses minimal disk space), and then:

    kvm -net nic,model=virtio -net user -m 1024 -vga vmware -usbdevice tablet -smp 2 -vnc :1 \
    -drive file=/home/roland/ubuntu-11.04-server-amd64.iso,media=cdrom,if=ide,boot=on \
    -drive file=d01,if=virtio,format=qcow2 \
    -drive file=d02,if=virtio,format=qcow2 \
    -drive file=d03,if=virtio,format=qcow2 \
    -drive file=d04,if=virtio,format=qcow2 \
    -drive file=d05,if=virtio,format=qcow2 \
    -drive file=d06,if=virtio,format=qcow2 \
    -drive file=d07,if=virtio,format=qcow2 \
    -drive file=d08,if=virtio,format=qcow2 \
    -drive file=d09,if=virtio,format=qcow2 \
    -drive file=d10,if=virtio,format=qcow2 \
    -drive file=d11,if=virtio,format=qcow2 \
    -drive file=d12,if=virtio,format=qcow2 \
    -drive file=d13,if=virtio,format=qcow2 \
    -drive file=d14,if=virtio,format=qcow2 \
    -drive file=d15,if=virtio,format=qcow2 \
    -drive file=d16,if=virtio,format=qcow2 \
    -drive file=d17,if=virtio,format=qcow2 \
    -drive file=d18,if=virtio,format=qcow2 \
    -drive file=d19,if=virtio,format=qcow2 \
    -drive file=d20,if=virtio,format=qcow2 \
    -drive file=d21,if=virtio,format=qcow2 \
    -drive file=d22,if=virtio,format=qcow2 \
    -drive file=d23,if=virtio,format=qcow2 \
    -drive file=d24,if=virtio,format=qcow2 \
    -drive file=d25,if=virtio,format=qcow2 \
    -drive file=d26,if=virtio,format=qcow2 \
    -drive file=d27,if=virtio,format=qcow2 \
    -drive file=d28,if=virtio,format=qcow2

(the first two lines can be tweaked for your ISO location and UI preferences). In this VM, I chose to use whole disk on /dev/vdaa in the partitioner, and I got the same error with grub-installer failing.

I'm currently poking around the grub-installer script to see what exactly is failing. In /var/log/syslog (in the installer), I just see:

    WARNING **: Configuring 'grub-installer' failed with error code 1

but no diagnostics from grub-installer that I can find.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: debian-installer (not installed)
Uname: Linux 2.6.39-999-generic x86_64
Architecture: amd64
Date: Tue May 3 11:26:53 2011
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha amd64 (20101206)
MachineType: LENOVO 2901CTO
MemoryUsage:
 total used free shared buffers cached
 Mem: 7987000 7830544 156456 0 290636 5617776
 -/+ buffers/cache: 1922132 6064868
 Swap: 1738748 620 1738128
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.39-999-generic root=UUID=ab1e5491-e40c-4113-bf20-22ecb604999a ro drm.debug=0xe
SourcePackage: debian-installer
UpgradeStatus: Upgraded to natty on 2011-03-24 (39 days ago)
dmi.bios.date: 10/27/2010
dmi.bios.vendor: LENOVO
dmi.bios.version: 6UET61WW (1.41 )
dmi.board.name: 2901CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr6UET61WW(1.41):bd10/27/2010:svnLENOVO:pn2901CTO:pvrThinkPadT410s:rvnLENOVO:rn2901CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 2901CTO
dmi.product.version: ThinkPad T410s
dmi.sys.vendor: LENOVO