Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 8 Jul 2018 16:08:04 +0300
From:      "Andrey V. Elsukov" <bu7cher@yandex.ru>
To:        Manish Jain <jude.obscure@yandex.com>, freebsd-fs@freebsd.org
Subject:   Re: A request for unnested UFS implementation in MBR
Message-ID:  <428ce38c-4f3b-1dff-36c5-4a7509613441@yandex.ru>
In-Reply-To: <98201d37-2d65-34c6-969e-c9649f1a3ab1@yandex.com>
References:  <98201d37-2d65-34c6-969e-c9649f1a3ab1@yandex.com>

next in thread | previous in thread | raw e-mail | index | archive | help
This is an OpenPGP/MIME signed message (RFC 4880 and 3156)
--URWZ9rmC3VsvqRyDFttqaR6ADl7DLOEjG
Content-Type: multipart/mixed; boundary="tmFV9ANBfumWRrFYdVk6kIVQbIndvvcsy";
 protected-headers="v1"
From: "Andrey V. Elsukov" <bu7cher@yandex.ru>
To: Manish Jain <jude.obscure@yandex.com>, freebsd-fs@freebsd.org
Message-ID: <428ce38c-4f3b-1dff-36c5-4a7509613441@yandex.ru>
Subject: Re: A request for unnested UFS implementation in MBR
References: <98201d37-2d65-34c6-969e-c9649f1a3ab1@yandex.com>
In-Reply-To: <98201d37-2d65-34c6-969e-c9649f1a3ab1@yandex.com>

--tmFV9ANBfumWRrFYdVk6kIVQbIndvvcsy
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: quoted-printable

On 07.07.2018 08:59, Manish Jain wrote:
> I am a longtime user of FreeBSD, which now serves as my only OS.
>=20
> There is one request I wished to make for FreeBSD filesystems. While UF=
S
> implementation under GPT is unnested just as Ext2, the MBR
> implementation of UFS continues to piggyback on an unnecessary nest (in=

> a BSD slice).
>=20
> Can it not be considered as an alternative to provide a UFS partition
> (unnested) under MBR too ?
>=20
> Existing users could continue to use the freebsd::freebsd-ufs scheme,
> while fresh usage could have the alternative of UFS directly recorded i=
n
> the MBR.
>=20
> I should perhaps note that unlike most users who have shifted to GPT of=

> late, I much prefer MBR because 1) the scheme's design by itself keeps
> the number of slices/partitions in a disk manageable; and 2) I can use
> the boot0 manager, my favourite boot manager.

The main goal of using bsdlabel was the boot code, I think.
MBR has less than 512 bytes to keep boot code. This is too little to be
able place the code that can read UFS filesystem to read and start loader=
=2E

I'm not sure, but AFAIR there were some hacks in the boot code, that
allowed to read from the raw partition as fallback.
I.e. you can try to create MBR with "freebsd" slice, make filesystem
with newfs on this slice and write boot1 bootcode to this slice at
proper offset using dd(1). But as I said, I'm not sure. There were many
changes in this area and I did not followed by them.

--=20
WBR, Andrey V. Elsukov


--tmFV9ANBfumWRrFYdVk6kIVQbIndvvcsy--

--URWZ9rmC3VsvqRyDFttqaR6ADl7DLOEjG
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: OpenPGP digital signature
Content-Disposition: attachment; filename="signature.asc"

-----BEGIN PGP SIGNATURE-----
Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/

iQEzBAEBCAAdFiEE5lkeG0HaFRbwybwAAcXqBBDIoXoFAltCDLQACgkQAcXqBBDI
oXrxmQgAp2X7eIydmjUrohz5TqGOjNEncJTkz5Dp77VBGHeOnLoKf3DqyiA9Owh8
3nyGZmQuIJKyZVWVLUqWFooDRHCmlP86mfh6dJDcxWQ1VKwiHRHnbxaLZbuFIkaN
VpCVnBxhxgzry5Gv6USx2uW3p5J8FVx5nM4MaiQzRXgCYP0fga25MplNqb2Zbxtl
UOsYDzkkSixUbw29IJNHg5u50Hj0VXANTnTSfm2wAxgmxb7lZry24s29dPnldLFW
awCma1+TyUBFHlAvHaMq9lvLrDeQpRPvwaAoFa3lGwKAVLGOFQMyh4PNb3sMvzkF
UC72fZUS7ZmAWl99YTNgRr4tfNkfEQ==
=GnE5
-----END PGP SIGNATURE-----

--URWZ9rmC3VsvqRyDFttqaR6ADl7DLOEjG--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?428ce38c-4f3b-1dff-36c5-4a7509613441>