[CentOS] /boot on a separate partition?

Thu Jun 25 21:20:09 UTC 2015
Stuart Barkley <stuartb at 4gh.net>

On Tue, 23 Jun 2015 at 09:27 -0000, Robert Heller wrote:

> Another advantage of having /boot on its own partition is supporting
> multiple linux flavors that is, it is possible to 'share' /boot
> between CentOS, Fedora, Ubuntu, Debian, etc. if one wants to,
> although it is really easier to pick one system for your 'host' and
> then install VMs for all of the others, but sometimes one needs to
> test things with different Linux flavors *on the bare metal* for
> various reasons.

This might work until the different OS installations start arguing
about the version of grub/grub2 and the contents of the grub
configuration file (including whose grub configuration files to use).
They tend to do this during kernel updates and at other times.

Having grub take over your main boot choice is as silly as Windows
assuming it is the only OS installed.

I have long preferred to use a single / partition for each OS
installation and put the system specific grub image in the individual
partition.  I use the 1 sector (MBR) FreeBSD bootloader to boot the
partition I want at boot time.  Note that grub2 doesn't like this and
spews an error message, but it does work (mostly) (grub2 needs to be
fixed to support this functionality and not assume it can become the
master boot process).

This does tend to limit you to 3 OS choices in the primary partitions
(assuming a 4th extended partition for data partitions).  That usually
is enough for my purposes.

With EFI systems, this is changing and my experiences are not complete
enough to have strong opinions.  It does look like the EFI boot
process conceptually handles this by letting the user choose which EFI
application to load first (using efimanager).  EFI disk based booting
does still need the DOS formatted partition often mounted at

For booting encrypted systems, I do put /boot in separate partitions
(with the corresponding / being an extended partition).  I still use a
separate MBR boot loader to select which /boot I use.

I've never been lost; I was once bewildered for three days, but never lost!
                                        --  Daniel Boone