From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ric Wheeler Subject: Re: What to do about the 2TB limit on HDIO_GETGEO ? Date: Tue, 25 Mar 2008 10:31:54 -0400 Message-ID: <47E90CDA.600@emc.com> References: <47E875AD.1000901@rtr.ca> <47E8FF58.8050209@rtr.ca> Reply-To: ric@emc.com Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <47E8FF58.8050209@rtr.ca> Sender: linux-scsi-owner@vger.kernel.org To: Mark Lord Cc: Linus Torvalds , Jens Axboe , Jeff Garzik , Tejun Heo , Greg KH l , Andrew Morton , Linux Kernel , IDE/ATA development list , linux-scsi List-Id: linux-ide@vger.kernel.org Mark Lord wrote: > Linus Torvalds wrote: >> >> On Mon, 24 Mar 2008, Mark Lord wrote: >>> The return value uses "unsigned long", >>> which on a 32-bit system limits drive offsets to 2TB. >> >> One relevant question is: does anybody seriously care about the >> combination of "32 bit" and "huge modern drives" any more? >> >> Sure, we can add a 64-bit version that ends up being used only on >> 32-bit systems, but quite frankly, I think the solution here is to >> just ignore the issue and see if anybody really even cares. >> >> Because quite frankly, the kind of people who buy modern 2TB drives >> generally don't then couple them to CPU's that are five+ years old. > .. > > Yeah. Except Dell will undoubtedly have them in desktops > within 2 years, and tons of people (myself included) still use > 32-bit (K)Ubuntu on our systems, simply for the better binary > compatibility that it is perceived to give with things like > browser plugins and stuff. I think that there are many embedded applications (lots of them linux based) which have large amounts of storage behind low power, low cost 32 bit CPU's. Think of the home/small office NAS boxes that you can get from bestbuy or other big box stores. Those devices today have 4 S-ATA drives (each of which can be 1TB in size). Also, if you have a very low end box, it can still access really large storage over iSCSI or a SAN which will present as a local, large device. Over time, even these low end CPU's will migrate towards 64 bits, but we are not there yet... ric