To enable multipath support during installation use

    install disk-detect/multipath/enable=true

at the installer prompt. If multipath devices are found these will show up as /dev/mapper/mpath<X> during installation.

Old and deprecacted information

/!\ grub2 has had multipath support since 1.99-12 (Debian 7, wheezy). All information below this point only applies to Debian versions older then that.

In order to test Multipath in d-i you still need a patched grub (442382) but see below.

Installing Grub Legacy

Since neither Debian's grub nor grub2 support multipath device names yet (483971), you have to manually install a patch grub legacy (442382) during installation. A prebuilt deb for i386 is available here. (In case you need to built for another architecture, the sources are available via this git tree).

Method 1

Proceed with the installation until the installer asks you if you want to install grub on the multipath device then:

Method 2

This method works if you're installing via a serial console and can't switch VTs. Finish the installation until you're asked to reboot. Then:

  chroot /target
  dpkg -i /tmp/grub*deb
  echo "(hd0) /dev/mapper/mpath0" > /boot/grub/
  grub --device-map=/boot/grub/

  root (hd0,0)
  setup (hd0)

Multipath Support in Debian Installer:


These are the know open issues for Squeeze, please test and provide feedback:


This needed/needs to be done to support multipathing natively in DebianInstaller: