From mboxrd@z Thu Jan 1 00:00:00 1970 From: Goswin von Brederlow Subject: Re: raid-0 with mdadm vs lvm striping Date: Mon, 17 Aug 2009 09:27:35 +0200 Message-ID: <878whix5lk.fsf@frosties.localdomain> References: <3ECBDC05781B3D48ABD520A01ABF2F9B2E99EDBB63@SE-EX008.groupinfra.com> <3ECBDC05781B3D48ABD520A01ABF2F9B2E9A0485D5@SE-EX008.groupinfra.com> <87vdkt4e5x.fsf@frosties.localdomain> <3ECBDC05781B3D48ABD520A01ABF2F9B2E9A048A82@SE-EX008.groupinfra.com> <874osc5ut5.fsf@frosties.localdomain> <687B35659F854CFF970C1AB11EF9954B@m5> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <687B35659F854CFF970C1AB11EF9954B@m5> (Guy Watkins's message of "Wed, 12 Aug 2009 22:40:19 -0400") Sender: linux-raid-owner@vger.kernel.org To: Guy Watkins Cc: 'Goswin von Brederlow' , 'Billy Crook' , "'Henry, Andrew'" , 'Drew' , linux-raid@vger.kernel.org List-Id: linux-raid.ids "Guy Watkins" writes: > } -----Original Message----- > } From: linux-raid-owner@vger.kernel.org [mailto:linux-raid- > } owner@vger.kernel.org] On Behalf Of Goswin von Brederlow > } Sent: Wednesday, August 12, 2009 10:09 PM > } To: Billy Crook > } Cc: Henry, Andrew; goswin-v-b@web.de; Drew; linux-raid@vger.kernel.= org > } Subject: Re: raid-0 with mdadm vs lvm striping > }=20 > } Billy Crook writes: > }=20 > } > On Wed, Aug 12, 2009 at 04:14, Henry, Andrew > } wrote: > } >> That's what my question was: =A0Will raid0 (striping) be faster = or easier > } to manage than lvm striping > } > > } > LVM striping won't change performance for small files. (That is f= iles, > } > smaller than the extent size.) To be fair, RAID-0 striping won't > } > accelerate file access for files smaller than the stripe size eit= her. > } > However, traditionally, raid0 stripe sizes are much much smaller = than > } > LVM extent sizes. Both are however adjustable. > }=20 > } That sucks. LVM striping really should have a setting where it stri= pes > } chunks within a PE. > }=20 > } MfG > } Goswin > > Why not use this option? Ignorance. :) I never use raid0 so I never needed to look for all the stripe parameters. > -I, --stripesize StripeSize > Gives the number of kilobytes for the granularity of the > stripes. StripeSize must be 2^n (n =3D 2 to 9) for metadata in LVM1 = format. > For metadata in LVM2 format, the stripe size may be a larger powe= r of 2 > but must not exceed the physical extent size. > > I have never use lvcreate with Linux, but have with HP-UX. Looks abo= ut the > same, but maybe I am confused. > > Guy MfG Goswin -- 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