[CentOS] /boot on a separate partition?

Thu Jun 25 19:27:47 UTC 2015
Chris Murphy <lists at colorremedies.com>

Timothy Murphy gayleard at eircom.net Tue Jun 23 12:49:08 UTC 2015
> Do most people today have /boot on a separate partition,
> or do they (you) have it on the / partition ?

Different distros have different defaults. There's no actual right or
wrong here. Pretty much anything you can think of can be made to work.

Jonathan Billings billings at negate.org  Tue Jun 23 13:28:18 UTC 2015
>Not only do I have a /boot partition, but I have a /boot/efi partition.

It's bad design. First, it's a nested mount: file system A on /, and
file system B on /boot, and file system C on /boot/efi. Therefore the
mount process must make sure they're mounted in that order, or there's
failure. Second, there is no good reason for the EFI System partition
to ever be mounted; and multiple reasons to not ever mount it (Windows
and OS X never mount the EFI System partition but somehow all the
Linux distros are obsessed with mounting things that don't need
mounting). Eventually systemd will become smarter and handle on-demand
dynamic mount and umount, including the ESP so this will get better
but even better would be not ever mounting it in the first place.

> I probably could get away without using the /boot partition, but I've
> been experimenting with btrfs and snapshots and it makes sense to keep
> /boot as an ext4 filesystem.

I disagree, yet I'm curious what example you have that this makes sense.

This ext4 /boot is unique to F/C/RH's dependency on grubby which
doesn't grok Btrfs subvolumes, and therefore kernel updates don't get
written to grub.cfg properly if /boot is on a Btrfs subvolume. GRUB,
including grub2-mkconfig figures out subvolumes just fine. It's
specifically a limitation of RH distros. Ubuntu and openSUSE don't
have this problem.

>I suspect with the move to XFS it might be a good idea to keep an ext4 /boot too.

There's no advantage to it being ext4. The default installation for
Fedora 22 Server, CentOS/RHEL 7 is /boot on XFS, and / on a separate
XFS, and /home on a separate XFS. Just like with ext4, except with

Chris Murphy