From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roberto Spadim Subject: Re: SSD - TRIM command Date: Tue, 8 Feb 2011 16:31:24 -0200 Message-ID: References: <4D517F4F.4060003@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <4D517F4F.4060003@gmail.com> Sender: linux-raid-owner@vger.kernel.org To: maurice Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids it's resync running? i don't think it's a problem... any device will die some day... ssd is faster than hd, why not use it? i'm using hp smart array p212 with 3.0 firmware, it write on all blocks= too maybe a just command line option to start array without sync could help= =2E.. i don't know if resync is write intensive or just write on diferent blocks, if it's just diff it's not a problem for ssd... again... i know that the 'translate' of trim command to non compatible devices is a problem for device layer not md layer, but can md send trim command to all mirrors/disks? 2011/2/8 maurice : > 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 compatib= le >> 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 manag= ement > utilities (such as mdadm) > write to all of the blocks on the storage device to ensure that check= sums > operate properly. > This will cause the performance of the SSD to degrade quickly. " > > https://docs.fedoraproject.org/en-US/Fedora/14/html/Storage_Administr= ation_Guide/newmds-ssdtuning.html > > > -- > Cheers, > Maurice Hilarius > eMail: /mhilarius@gmail.com/ > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid"= in > the body of a message to majordomo@vger.kernel.org > More majordomo info at =A0http://vger.kernel.org/majordomo-info.html > --=20 Roberto Spadim Spadim Technology / SPAEmpresarial -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html