From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martin K. Petersen" Subject: Re: Adding a smaller drive Date: Sun, 05 Jul 2009 20:05:53 -0400 Message-ID: References: <20090703154609101.MIIG19322@cdptpa-omta02.mail.rr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <20090703154609101.MIIG19322@cdptpa-omta02.mail.rr.com> (Leslie Rhorer's message of "Fri, 3 Jul 2009 10:46:21 -0500") Sender: linux-raid-owner@vger.kernel.org To: lrhorer@satx.rr.com Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids >>>>> "Leslie" == Leslie Rhorer writes: >> I do think, however, that you are underestimating the power of >> industry associations and standards bodies. System manufacturers, >> enterprise customers and governments absolutely refuse to buy things >> that are not compliant. So this is not about whether you can legally >> cut corners. It is about being able to sell your product in the >> first place. Leslie> So a company like Apple could never compete with IBM? Who says that Apple doesn't care about the LBA count? Most desktop system vendors use disk imaging to perform burn-in and software preload. It matters to them. Same goes for OS deployment on the business desktop end of things. I don't have any idea whether more desktop class drives are sold individually as opposed to as part of a new computer. But that doesn't really matter. Because fact is that it's the system vendors that set the bar for standards compliance. I am not sure what the incentive would be for the drive vendors to provide different capacities/firmware loads for drives sold directly to consumers. Until the IDEMA LBA spec was ratified we were talking about capacity variations of a few percent within a given class. I don't think consumers care about that nearly as much as we computer professionals do. Leslie> There are myriad examples of non-compliant software and hardware Leslie> being developed in a standards-based environment yet selling Leslie> very well. I think maybe you are underestimating the vast Leslie> buying power of individual consumers and non-enterprise Leslie> businesses. I don't disagree that there's a lot of crap hardware out there. Absolutely. And a sizable portion of said crap is in the USB-ATA bridge designed-by-dyslexic-monkeys category. However, there's only a handful of disk drive manufacturers. And they are all pretty good at adhering to existing standards for the reasons I outlined earlier. Namely that they have to sell exactly the same drives to customers with higher standards than aforementioned dyslexic monkeys. Here's the LBA count for a bunch of currently shipping 3.5" 1TB drives that I was able to find the data sheets for within a couple of minutes of googling: DRIVE LBA COUNT --------------------------------------------- Hitachi Deskstar 7K1000: 1,953,525,168 Hitachi Deskstar 7K1000.B: 1,953,525,168 Seagate Barracuda ES.2: 1,953,525,168 Seagate Barracuda 7200.11: 1,953,525,168 Seagate Barracuda 7200.12: 1,953,525,168 Seagate Barracuda LP: 1,953,525,168 Samsung SpinPoint F1 DT: 1,953,525,168 Samsung Ecogreen F2: 1,953,525,168 WDC Caviar Black: 1,953,525,168 WDC Caviar Green: 1,953,525,168 WDC Caviar RE3: 1,953,525,168 WDC Caviar RE2-GP: 1,953,525,168 --------------------------------------------- Leslie> Well, first of all, in this very thread someone gave an example Leslie> of a modern drive which is apparently non-compliant. That turned out to be a drive sitting behind a RAID controller which reserves a portion of the drive for its own use. -- Martin K. Petersen Oracle Linux Engineering