I installed Debian Jessie on a LVM in a software RAID 1.
To make sure MBR are written on both disks of the RAID 1, I run dpkg-reconfigure grub-pc (as suggested here) and select both disks.
I get those errors :
root@bouzin:/home/jerome# dpkg-reconfigure grub-pc
Installing for i386-pc platform.
File descriptor 3 (pipe:[1038681]) leaked on vgs invocation. Parent PID 4760: grub-install
File descriptor 3 (pipe:[1038681]) leaked on vgs invocation. Parent PID 4760: grub-install
File descriptor 3 (pipe:[1038681]) leaked on vgs invocation. Parent PID 4760: grub-install
Installation finished. No error reported.
Installing for i386-pc platform.
File descriptor 3 (pipe:[1038681]) leaked on vgs invocation. Parent PID 4789: grub-install
File descriptor 3 (pipe:[1038681]) leaked on vgs invocation. Parent PID 4789: grub-install
File descriptor 3 (pipe:[1038681]) leaked on vgs invocation. Parent PID 4789: grub-install
Installation finished. No error reported.
Generating grub configuration file ...
Found background image: /usr/share/images/desktop-base/desktop-grub.png
Found linux image: /boot/vmlinuz-3.16.0-4-amd64
Found initrd image: /boot/initrd.img-3.16.0-4-amd64
done
Is this something to be worried about ?
This bug report suggests such warnings may appear and are harmless, but those should have been fixed already AFAIU.
More details on my install, in case it would be relevant :
I use 2 hard drives. On each drive is a single whole-drive partition used for the RAID. I create one RAID1 with both partitions. I create a LVM on the RAID and create 3 logical volumes in the LVM for swap, / and /home.
During installation, I only wrote the MBR on one drive, either by mistake or because the installer wouldn't allow me to write it on both. I want to be able to boot with only one drive, so I need the MBR written on both drives.