From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 5 Jul 2002 11:36:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 5 Jul 2002 11:36:34 -0400 Received: from rwcrmhc52.attbi.com ([216.148.227.88]:9609 "EHLO rwcrmhc52.attbi.com") by vger.kernel.org with ESMTP id ; Fri, 5 Jul 2002 11:36:31 -0400 Message-ID: <3D25BB54.7010005@namesys.com> Date: Fri, 05 Jul 2002 19:29:24 +0400 From: Hans Reiser User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.0) Gecko/20020529 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Peter Chubb CC: reiserfs-dev@namesys.com, gelato@gelato.unsw.edu.au, linux-kernel@vger.kernel.org, Oleg Drokin Subject: Re: [reiserfs-dev] Results of testing Reiserfs on large block devices. References: <15653.12329.565726.228100@wombat.chubb.wattle.id.au> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Peter Chubb wrote: >Hi folks, > I couldn't get Reiserfs to work on large devices. I've tracked the >problem down. > > When Reiserfs is mounted, it tries to allocate a chunk of memory for >bitmaps using kmalloc. The largest chunk allocatable by kmalloc is >128k. This limits the size of a reiserfs to just under 2TB on a >64-bit platform (16384 bitmaps times 8bytes per pointer) or just under >4TB on a 32 bit platform (32768 bitmaps times 4bytes per pointer). > >This reasoning assumes that the number of bitmaps is given by the >formula (number_of_blocks + (8 * blocksize - 1))/(8 * blocksize) where >blocksize is 4096 bytes. Thus > number_of_blocks = 8 * 4096 * (16384 - 1) - 1 [64 bit] > > number_of_blocks = 8 * 4096 * (32768 - 1) - 1 [32 bit] > >Hacking mm/slab.c to increase the memory limit allowed larger >filesystems to be mounted, but I haven't tested these thoroughly yet. >-- >Dr Peter Chubb peterc@gelato.unsw.edu.au >You are lost in a maze of BitKeeper repositories, all almost the same. > > > > > Thanks for figuring this out. Oleg will fix it. -- Hans