Date: Fri, 1 Jan 2016 22:35:51 +0300 From: "Eugene R" <genie@geniechka.ru> To: "Brandon J. Wandersee" <brandon.wandersee@gmail.com> Cc: <freebsd-questions@freebsd.org> Subject: Re: freebsd-update for architecture migration? Message-ID: <AB3CA610214E4952A8790E8B179E5521@geniepc2011> In-Reply-To: <86k2nt3yc1.fsf@WorkBox.Home> References: <5C0285423A864DB1A8893E704BE3118C@geniepc2011> <86k2nt3yc1.fsf@WorkBox.Home>
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Hi!
As I said, mostly this is for migration from x86 to amd64, when the hardware
is basically the same.
Many people think (thought) that for a <=3GB memory machine (physical or
virtual) using amd64 does not make sense (and makes some overhead) even
though it would run perfectly well on any x86-type machine made in recent 10
years or so.
But when going to 4 or 8 GB or just changing the virtual server, all the
memory above 3GB is wasted.
When upgrading from 8.x to 9.x or 10.x you also have to change the kernel
and everything.
And of course the problem is not installing the bare new system, but
installing and configuring all the system and third-party software
components to get the same running environment. Otherwise you might say "why
anyone needs upgrade option, just reinstall everything from scratch" =))
Best wishes
Eugene
-----Original Message-----
From: Brandon J. Wandersee
Sent: Friday, January 01, 2016 10:15 PM
To: Eugene R
Cc: freebsd-questions@freebsd.org
Subject: Re: freebsd-update for architecture migration?
Eugene R writes:
> Does it makes sense?
No. First, it could only possibly work if the foundational architecture
were fundamentally the same--say, moving from x86 to x86-64. You can't
move from x86 to ARM, because the live x86 system wouldn't run on the
new hardware. And as x86 becomes obsolete instances of people moving
from x86 to x86-64 will dwindle drastically in the near future, such
that by the time the work to make this possible were finished and the
new freebsd-update version released, it would no longer be useful. And
I'm not sure why you think migrating to a new architecture would be
simpler than just upgrading the current system, since you'd have to
replace each and every file, including the kernel. You'd be replacing
the currently running kernel with one specific instruction set on the
live system, with a new one using a different instruction set. I would
bet the system would almost certainly lock up.
That's all kinda moot, though, because if you're moving from one
architecture to another, then unless you've got some extraordinarily
special circumstance, you're logically moving from one machine to
another. A new machine with different hardware requiring different
configurations and different port/package builds, and probably some
other stuff you'll almost certainly forget in the process. It would be
much faster to just install a new system from scratch.
--
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:: brandon.wandersee@gmail.com ::
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