Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965134AbWIEPir (ORCPT ); Tue, 5 Sep 2006 11:38:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965141AbWIEPir (ORCPT ); Tue, 5 Sep 2006 11:38:47 -0400 Received: from mail.lysator.liu.se ([130.236.254.3]:8358 "EHLO mail.lysator.liu.se") by vger.kernel.org with ESMTP id S965134AbWIEPip (ORCPT ); Tue, 5 Sep 2006 11:38:45 -0400 To: Xavier Bestel Cc: linux-kernel@vger.kernel.org Subject: Re: VFAT truncate performance References: <1157468114.1435.216.camel@capoeira> From: =?iso-8859-1?Q?Mattias_R=F6nnblom?= Date: 05 Sep 2006 17:38:48 +0200 In-Reply-To: <1157468114.1435.216.camel@capoeira> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.4 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1406 Lines: 30 Xavier Bestel writes: > On Tue, 2006-09-05 at 15:52, Mattias R?nnblom wrote: > > Hi, > > > > extending files by ftruncate(2) runs very slow on VFAT file > > systems. On my USB harddisk w/ VFAT, it takes 14 seconds to extend an > > empty file to 1 GB. On a memory stick, it takes well over 4 minutes. > > > > My question is: is this problem on the conceptual level (ie there is > > no way of extending files on FAT that doesn't involve many disk > > operations) or is the current Linux fs driver suboptimal in this > > respect? > > > > The reason for asking is that I run Samba which service files on USB > > devices (w/ VFAT for portability) to Windows XP clients. When copying > > files to the Samba server, Microsoft SMB clients seem to extend the > > file before actually starting to copy the data. This results in > > sluggishness and timeouts when copying large files to VFAT > > filesystems. > > Is your USB stick mounted -o sync ? If that's the case, the truncate() > and write() won't be merged so they will take twice as long. -o sync > generally kills performance on USB sticks. > No, 'async'. Regards, Mattias - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/