From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Guy Watkins" Subject: RE: raid-0 with mdadm vs lvm striping Date: Wed, 12 Aug 2009 22:40:19 -0400 Message-ID: <687B35659F854CFF970C1AB11EF9954B@m5> References: <3ECBDC05781B3D48ABD520A01ABF2F9B2E99EDBB63@SE-EX008.groupinfra.com><3ECBDC05781B3D48ABD520A01ABF2F9B2E9A0485D5@SE-EX008.groupinfra.com><87vdkt4e5x.fsf@frosties.localdomain><3ECBDC05781B3D48ABD520A01ABF2F9B2E9A048A82@SE-EX008.groupinfra.com> <874osc5ut5.fsf@frosties.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <874osc5ut5.fsf@frosties.localdomain> Sender: linux-raid-owner@vger.kernel.org To: 'Goswin von Brederlow' , 'Billy Crook' Cc: "'Henry, Andrew'" , 'Drew' , linux-raid@vger.kernel.org List-Id: linux-raid.ids } -----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.or= g } 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 fil= es, } > smaller than the extent size.) To be fair, RAID-0 striping won't } > accelerate file access for files smaller than the stripe size eithe= r. } > However, traditionally, raid0 stripe sizes are much much smaller th= an } > LVM extent sizes. Both are however adjustable. }=20 } That sucks. LVM striping really should have a setting where it stripe= s } chunks within a PE. }=20 } MfG } Goswin Why not use this option? -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 fo= rmat. =46or 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 about= the same, but maybe I am confused. Guy -- 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