From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stan Hoeppner Subject: Re: The chunk size paradox Date: Thu, 02 Jan 2014 16:42:42 -0600 Message-ID: <52C5EB62.1090807@hardwarefreak.com> References: <52C1C01A.7010407@ubuntu.com> <52C57C7B.80400@shiftmail.org> <52C588A7.6010207@hardwarefreak.com> <52C59468.6080200@ubuntu.com> <52C5A9AA.9090300@hardwarefreak.com> <52C5BC28.2020003@gmail.com> Reply-To: stan@hardwarefreak.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <52C5BC28.2020003@gmail.com> Sender: linux-raid-owner@vger.kernel.org To: Joe Landman , Phillip Susi , joystick Cc: linux-raid List-Id: linux-raid.ids On 1/2/2014 1:21 PM, Joe Landman wrote: > On 01/02/2014 01:02 PM, Stan Hoeppner wrote: >> On 1/2/2014 10:31 AM, Phillip Susi wrote: >>> On 1/2/2014 10:41 AM, Stan Hoeppner wrote: >>>> First, there is no such thing as a 4K sector in Linux. Sectors are >>>> 512 bytes. Filesystem blocks and memory pages are 4K. >>> >>> Of course there is. Disks with 4k sectors are becoming more and more >>> popular. >> >> Please read: https://en.wikipedia.org/wiki/Advanced_Format >> >> There are no native 4K sector drives on the market. Linux does not > > Untrue. > > http://storage.toshiba.eu/cms/en/hdd/hard_disk_drives/product_detail.jsp?productid=452 >From that page: Physical parameters Bytes/sector (Host) 512 Bytes/sector (Disk) 4096 kByte > > http://www.seagate.com/www-content/product-content/constellation-fam/constellation-cs/en-us/docs/terascale-hdd-data-sheet-ds1793-1-1306us.pdf >From that page: Configuration Heads/Disks 8/4 Bytes per Sector (512-byte emulation) 4096 Damn, you had me salivating Joe. These are both AF 512e drives, not native 4K. > and many others. I've not yet seen an announcement from anyone. I'm not all seeing, but I'd think such an announcement would cross my RADAR. > 512 byte sector native drives are now far less common, with many of the > drives being native 4096 bytes with a translation layer for legacy > systems that require 512 bytes. This is infamous for wreaking havoc > with alignment. Exactly. Which is why so many of us wish native 4K drives would be released. And, again, AFAIK, nobody is shipping a native drive. They're all still 512e. I'd love for someone to prove me wrong here by pointing one out that is available, preferably more than one. -- Stan