From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from luka.romanrm.net ([213.163.64.74]:36346 "EHLO luka.romanrm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751157AbaB1HhO (ORCPT ); Fri, 28 Feb 2014 02:37:14 -0500 Date: Fri, 28 Feb 2014 13:37:12 +0600 From: Roman Mamedov To: Duncan <1i5t5.duncan@cox.net> Cc: linux-btrfs@vger.kernel.org Subject: Re: Help with space Message-ID: <20140228133712.3d0eef21@natsu> In-Reply-To: References: <20140228103436.2dfd2669@natsu> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/V0quPe2CMnn/1HsL7hX/yHB"; protocol="application/pgp-signature" Sender: linux-btrfs-owner@vger.kernel.org List-ID: --Sig_/V0quPe2CMnn/1HsL7hX/yHB Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Fri, 28 Feb 2014 07:27:06 +0000 (UTC) Duncan <1i5t5.duncan@cox.net> wrote: > Based on what I've read on-list, btrfs is not arch-agnostic, with certain= =20 > on-disk sizes set to native kernel page size, etc, so a filesystem=20 > created on one arch may well not work on another. >=20 > Question: Does this apply to x86/amd64? Will a filesystem created/used=20 > on 32-bit x86 even mount/work on 64-bit amd64/x86_64, or does upgrading=20 > to 64-bit imply backing up (in this case) double-digit TiB of data to=20 > something other than btrfs and testing it, doing a mkfs on the original=20 > filesystem once in 64-bit mode, and restoring all that data from backup? Page size (4K) is the same on both i386 and amd64. It's also the same on AR= M. Problem arises only on architectures like MIPS and PowerPC, some variants of which use 16K or 64K page sizes. Other than this page size issue, it has no arch-specific dependencies, e.g. no on-disk structures with "CPU-native integer" sized fields etc, that'd be= too crazy to be true. --=20 With respect, Roman --Sig_/V0quPe2CMnn/1HsL7hX/yHB Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlMQPKgACgkQTLKSvz+PZwhrEQCfcalfR15vDwpWxLamKvMtRpO7 IT8An29+xNqaPRwjqIDlZhgUlbmBVLUp =MKHj -----END PGP SIGNATURE----- --Sig_/V0quPe2CMnn/1HsL7hX/yHB--