From mboxrd@z Thu Jan 1 00:00:00 1970 From: Volker Lendecke Subject: Re: Samba speed Date: Tue, 9 Dec 2008 08:50:56 +0100 Message-ID: References: <20081208182114.GD29163@samba1> <20081208223924.GB2501@mit.edu> <20081208231233.GK29163@samba1> <20081208233802.GD2501@mit.edu> <20081209003701.GE16818@webber.adilger.int> <20081209060650.GD10270@mit.edu> <20081209065509.GB13153@mit.edu> Reply-To: Volker.Lendecke@SerNet.DE Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="aM3YZ0Iwxop3KEKx" Cc: Andreas Dilger , samba-technical@samba.org, linux-fsdevel , linux-cifs-client@lists.samba.org, Jeremy Allison To: Theodore Tso Return-path: Content-Disposition: inline In-Reply-To: <20081209065509.GB13153@mit.edu> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: samba-technical-bounces+gnsi-samba-technical=m.gmane.org@lists.samba.org Errors-To: samba-technical-bounces+gnsi-samba-technical=m.gmane.org@lists.samba.org List-Id: linux-fsdevel.vger.kernel.org --aM3YZ0Iwxop3KEKx Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Dec 09, 2008 at 01:55:09AM -0500, Theodore Tso wrote: > On Tue, Dec 09, 2008 at 05:25:29PM +1100, ronnie sahlberg wrote: > >=20 > > Its not as simple as "the redirector does it every 128k". the > > redirector does this but it varies from run to run and from client to > > client. > > It is very common to see this happening in 60-64kb strides and other > > strides as well. > >=20 > > It is probably some interaction with how large the actual i/o that the > > application did internally to the cache and some other thing. > > but anyway, it varies a lot. it is not always 128k. >=20 > Is there a maximum stride size used by the redirector? i.e., will it > use something bigger than 128k? In any case, increasing the ext3 > reservation window size should still be helpful. It's OK if we > increase it to 32 blocks (128k, on a 4k block filesystem), and the > stride size is smaller than that. But if it is often bigger than > 128k, then then it would probably be better if samba used the > EXT3_IOC_SETRSVSZ ioctl to dynamically set the reservation size as > appropriate. One might try to use "dd" from Cygwin on Windows. When I once analyzed this behaviour, the 1-byte writes were exactly at the end of the block the Win32 app gave to the kernel as seen by the sysinternals filemon tool. Volker --aM3YZ0Iwxop3KEKx Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) iD8DBQFJPiNfbsgDfmnSbrYRAgWdAJ9uPZhLRkkoOUita8wuhOKorpJ0fgCfQJkT /ZKXL9nBO4Tdorzgf8h1edc= =wWfd -----END PGP SIGNATURE----- --aM3YZ0Iwxop3KEKx--