From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Eric D. Mudama" Subject: Re: SSD - TRIM command Date: Mon, 21 Feb 2011 19:01:18 -0700 Message-ID: <20110222020118.GA30426@bounceswoosh.org> References: <4D62CF5F.6080007@cfl.rr.com> <20110222003610.GB29101@bounceswoosh.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Roberto Spadim Cc: Mathias =?iso-8859-1?Q?Bur=E9n?= , "Eric D. Mudama" , Phillip Susi , David Brown , linux-raid@vger.kernel.org List-Id: linux-raid.ids On Mon, Feb 21 at 22:55, Roberto Spadim wrote: >it can be used for badblock reallocation if harddisk have it >a harddisk is near to NOR ssd with variable accesstime, if head is >near sector to be read/write accesstime is small, if sector is far >from head, access time increase (normaly <=1 disk revolution if head >control system is good, for 7200rpm 1revolution is near to 8.33ms) Hard disks do not expose their defect information/remappings. They present a defect-free logical region to the host. Optimizing for a few hundred thousand remapped sectors across the LBA range of ~6 billion LBAs on a 3TB drive isn't worth the effort or code complexity in most cases. I still don't see how TRIM helps a rotating drive. -- Eric D. Mudama edmudama@bounceswoosh.org