Date: Tue, 1 Apr 2008 19:05:21 +0100 From: Peter Schuller <peter.schuller@infidyne.com> To: freebsd-current@freebsd.org, d@delphij.net Cc: Ivan Voras <ivoras@freebsd.org> Subject: Re: Are large RAID stripe sizes useful with FreeBSD? Message-ID: <200804012005.32581.peter.schuller@infidyne.com> In-Reply-To: <47F133AE.2010900@delphij.net> References: <fsr7fb$hl0$1@ger.gmane.org> <47F133AE.2010900@delphij.net>
next in thread | previous in thread | raw e-mail | index | archive | help
--nextPart1774646.OXeITV98u8 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline > Short answer: yes. Larger stripe sizes would allow better performance > for continuous read/write. In theory they will negatively affect small > size read/write but in practice you will notice that larger stripe size > would give better performance in almost all cases. One case where I have used large stripe sizes (though not with hardware rai= d=20 and not with FreeBSD) is with concurrent small reads (small =3D seek is the= =20 dominant cost) on top of a device of many drives. In these cases you want t= o=20 minimize the chance that a particular read will span multiple stripes, such= =20 that only a single drive will take a seek hit for a given request. This in= =20 turn maximizes actual physical concurrency when under high load (=3Dhigh=20 incoming request concurrency). =2D-=20 / Peter Schuller PGP userID: 0xE9758B7D or 'Peter Schuller <peter.schuller@infidyne.com>' Key retrieval: Send an E-Mail to getpgpkey@scode.org E-Mail: peter.schuller@infidyne.com Web: http://www.scode.org --nextPart1774646.OXeITV98u8 Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.8 (FreeBSD) iEYEABECAAYFAkfyeWwACgkQDNor2+l1i32B8ACgzhCc06rY/6YTWkPPOB/kVBQk Q3MAn2FqwhLtk3RoF9dhTjQ69GVf+Nw8 =a3dk -----END PGP SIGNATURE----- --nextPart1774646.OXeITV98u8--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200804012005.32581.peter.schuller>