From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boaz Harrosh Subject: Re: [Bug 12207] block reads/writes > 122880 bytes to USB tape drive gives EBUSY Date: Tue, 23 Dec 2008 16:47:31 +0200 Message-ID: <4950FA03.9080106@panasas.com> References: <20081223135938.30266108042@picon.linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from ey-out-2122.google.com ([74.125.78.27]:32032 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751113AbYLWOrj (ORCPT ); Tue, 23 Dec 2008 09:47:39 -0500 Received: by ey-out-2122.google.com with SMTP id 22so273877eye.37 for ; Tue, 23 Dec 2008 06:47:36 -0800 (PST) In-Reply-To: <20081223135938.30266108042@picon.linux-foundation.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: bugme-daemon@bugzilla.kernel.org Cc: linux-scsi@vger.kernel.org bugme-daemon@bugzilla.kernel.org wrote: > http://bugzilla.kernel.org/show_bug.cgi?id=12207 > > > > > > ------- Comment #6 from stern@rowland.harvard.edu 2008-12-23 05:59 ------- > You can change the max_sectors setting through sysfs. However the last time I > looked, the block layer limited max_sectors to 512 KB or something on that > order, so you can't get too much improvement. > > Why is a limit of 120 KB unreasonably small? All it means is that you have to > use more system calls to transfer the same amount of data. Is anything wrong > with that? > > This is not true BIOs can be chained and also SGs can be chained. You should be able to configure a very large transfer Boaz