From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753854AbYCJEdB (ORCPT ); Mon, 10 Mar 2008 00:33:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751099AbYCJEcw (ORCPT ); Mon, 10 Mar 2008 00:32:52 -0400 Received: from smtp.seznam.cz ([77.75.72.43]:54116 "HELO smtp.seznam.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1750819AbYCJEcw (ORCPT ); Mon, 10 Mar 2008 00:32:52 -0400 From: "Frantisek Rysanek" To: linux-kernel@vger.kernel.org Date: Mon, 10 Mar 2008 05:32:48 +0100 MIME-Version: 1.0 Subject: Re: block layer / FS question: x86_32bit with LBD, 20 TB RAID volume => funny issues Message-ID: <47D4C800.4273.B14F3D3A@Frantisek.Rysanek.post.cz> In-reply-to: <20080309220547.GR155407@sgi.com> References: <47D06F77.29711.A05566EC@Frantisek.Rysanek.post.cz>, <20080309220547.GR155407@sgi.com> X-mailer: Pegasus Mail for Windows (4.41) Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Content-description: Mail message body X-Smtpd: 1.0.32@12660 X-Seznam-User: frantisek.rysanek@post.cz Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9 Mar 2008 at 23:05, David Chinner wrote: > > Sure. the largest address space that can be used on a 32bit platform > with 4k pages is 16TB (2^32 * 2^12 = 2^44 = 16TB). For XFS, that means > metadata can't be placed higher in the filesystem than 16TB, and seeing > as we only have a single address space for metadata, the filesystem is > limited to 16TB. It could be fixed with software changes, but really > there's no excuse for using x86 given how cheap x86_64 is now..... > [...] > > Yes, switching to 64 bit machines will fix this problem as the > address space will now hold 2^64*2^12 bytes..... > wow, thanks for such a precise answer, from such an authoritative source :-) Frank Rysanek