From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martin K. Petersen" Subject: Re: [PATCH 4 of 8] sd: Physical block size and alignment support Date: Thu, 23 Apr 2009 14:25:54 -0400 Message-ID: References: <20090423163700.GB8350@mars.virtualiron.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from rcsinet11.oracle.com ([148.87.113.123]:19070 "EHLO rgminet11.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753711AbZDWS1h (ORCPT ); Thu, 23 Apr 2009 14:27:37 -0400 In-Reply-To: <20090423163700.GB8350@mars.virtualiron.com> (Konrad Rzeszutek's message of "Thu, 23 Apr 2009 12:37:00 -0400") Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Konrad Rzeszutek Cc: "Martin K. Petersen" , rwheeler@redhat.com, snitzer@redhat.com, jeff@garzik.org, neilb@suse.de, James.Bottomley@hansenpartnership.com, dgilbert@interlog.com, jens.axboe@oracle.com, linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org >>>>> "Konrad" == Konrad Rzeszutek writes: [Printing physical block size] Konrad> With the changes in the read_capacity_16 (where you set the Konrad> hw_sector_size) this won't be printed (at least on first probe). Why not? [root@10 ~]# modprobe scsi_debug dev_size_mb=1024 num_parts=4 physblk_exp=3 scsi 6:0:0:0: Direct-Access Linux scsi_debug 0004 PQ: 0 ANSI: 5 sd 6:0:0:0: Attached scsi generic sg3 type 0 sd 6:0:0:0: [sdc] 2097152 512-byte logical blocks: (1.07 GB/1.00 GiB) sd 6:0:0:0: [sdc] 4096-byte physical blocks Konrad> Another question - should the Documentation/*.txt have an entry Konrad> about what a 'logical block', and 'physical block' is Konrad> vs. 'hardware sector' ? Well, another item on my todo list is to kill the notion of hardware sector completely. The protocols have been referring to logical blocks for ages. It hasn't been a big problem until now because logical block size has been equal to the hardware sector size. That's no longer a valid assumption. -- Martin K. Petersen Oracle Linux Engineering