From mboxrd@z Thu Jan 1 00:00:00 1970 From: maurice Subject: Re: SSD - TRIM command Date: Tue, 08 Feb 2011 10:37:19 -0700 Message-ID: <4D517F4F.4060003@gmail.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Roberto Spadim Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 2/7/2011 1:07 PM, Roberto Spadim wrote: > hi guys, could md send TRIM command to ssd? using ext4 discart mount option? > if i mix ssd and hd, could this TRIM be rewrite to non TRIM compatible disks? > I have read that using md with SSDs is not a great idea: Form the Fedora 14 documentation: "Take note as well that software RAID levels 1, 4, 5, and 6 are not recommended for use on SSDs. During the initialization stage of these RAID levels, some RAID management utilities (such as mdadm) write to all of the blocks on the storage device to ensure that checksums operate properly. This will cause the performance of the SSD to degrade quickly. " https://docs.fedoraproject.org/en-US/Fedora/14/html/Storage_Administration_Guide/newmds-ssdtuning.html -- Cheers, Maurice Hilarius eMail: /mhilarius@gmail.com/