From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?Q?Mathias_Bur=C3=A9n?= Subject: Re: Software RAID and TRIM Date: Tue, 28 Jun 2011 17:11:04 +0100 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Tom De Mulder Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 28 June 2011 16:31, Tom De Mulder wrote: > Hi, > > > I'm investigating SSD performance on Linux, in particular for RAID de= vices. > > As I understand it=E2=80=94and please correct me if I'm wrong=E2=80=94= currently software > RAID does not pass through TRIM to the underlying devices. TRIM is es= sential > for the continued high performance of SSDs, which otherwise degrade o= ver > time. > > I don't think there would be any harm in this command being passed th= rough > to underlying devices if they don't support it (they would just ignor= e it), > and if they do it would make high-performance software RAID of SSDs a > possibility. > > > Is this something that's in the works? > > > > Many thanks, > > -- > Tom De Mulder - Cambridge University Computing Serv= ice > +44 1223 3 31843 - New Museums Site, Pembroke Street, Cambridge CB2 3= QH > -> 28/06/2011 : The Moon is Waning Crescent (22% of Full) IIRC md can already pass TRIM down, but I think the filesystem needs to know about the underlying architecture, or something, for TRIM to work in RAID. There's numerous discussions on this in the archives of this mailing list. /M -- 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