What is the "better / best " method to multi-boot different OSes natively WITHOUT VirtualBox(es) ?

[Ralf Mardorf]

On Sat, 24 Oct 2020 11:10:10 +0100, Steve O'Hara-Smith wrote:
>bot swap drive bay

On another mailing list a woman does use a selection switch thingy. I
don't remember what it is called. The drives are on-board, but only a
selected drive is connected and turned on.

A hot swap drive bay inherits the risk of a damage by static
electricity when changing drives.

I also want to add for consideration, if reboots between operating
systems are often wanted and HDDs are used, it's way better when all
drives, even the unused drives are spinning all the time. Parking and
releasing heads very often, does shorten the life span the most.

If sharing data between operating systems is wanted, it requires
organizational measures. Sometimes it's maybe wasting resources to use
a separated drive.

Btw. I once used GRUB (legacy or 2, I don't remember) to multi-boot
between FreeBSD, Windows (98 and/or XP, I don't remember) and several
Linux installs, on a BIOS machine (definitively no EFI secure
whatsoever thingy). FreeBSD and Windows via chain loading. I never
experienced an issue. Installing the operating systems was easy, too.

Nowadays I'm using syslinux to boot between several Linux installs,
FreeBSD is on an USB stick and apart from this I'm using iPads and
Windows XP, 7 and 10 are running on a VirtualBox Linux host, which is a
super advantage, if restoring a broken Windows is required ot to share
data.

In my experiences there never was an issue that one install messed up
the other install or at least the boot loader. The real issue (when
using different operating systems on one machine, as I've done in the
past or the way I'm doing it at the moment, by using an USB stick and
tablets) is, sharing data between operating systems.

An example I'm experiencing at the moment. To share data between
Linux and iPadOS I could use (ex)fat or hfs+. When storing the Linux
data on (ex)fat partitions, permissions get lost, so (ex)fat is no
option at all. Actually I'm using hfs+, so Linux can store
permissions, but after the drive was used by iPadOS, under Linux I need
to run fsck.hfsplus to gain write access, even if fsck.hfsplus just
mentions, that everything is ok (and journaling is disabled), it
seemingly repairs something without mentioning it. Without running
fsck.hfsplus file system access is read only or results in an
input/outout error. The new drive seems not to be broken. Maybe
something is fishy with my USB 3 ports, OTOH I rarely experience USB
issues, so I guess even the input/output errors are related to a file
system inconsistency and not to a hardware related issue.