From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linda Walsh Subject: Port Multiplier access with Sil 3124 Date: Sun, 08 Feb 2009 12:38:14 -0800 Message-ID: <498F42B6.8030607@tlinx.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from ishtar.tlinx.org ([64.81.245.74]:32776 "EHLO ishtar.tlinx.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751449AbZBHVIs (ORCPT ); Sun, 8 Feb 2009 16:08:48 -0500 Received: from [192.168.3.11] (Athena [192.168.3.11]) by ishtar.tlinx.org (8.14.1/8.12.10/SuSE Linux 0.7) with ESMTP id n18KcFvO015676 for ; Sun, 8 Feb 2009 12:38:15 -0800 Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: linux-ide@vger.kernel.org Is there something different, from normal disk-access, that I need to do to access hard disks beyond '1', on a port-multiplier? I thought I remembered reading the port multiplier support was working for many SATA and SATA RAID controller capable chipsets, including the Sil 3124. I picked up a 2-Bay external SATA enclosure that I'm trying to access in (what I thought) was the simplest mode: "JBOD". However, when I boot, I am only seeing the first hard disk. Experimenting, I tried a single hard disk in both positions -- one position let me see the disk directly (as though it was a direct, str8-thru connection), the other position showed up detected by the boot BIOS as a 7MB HD by some unrecognized vendor. In linux, I'm able to access and use the hard disk when it appears 'str8-thru', but linux sees nothing concerning the 7MB pseudo HD. Is my expectation that the driver would simply recognize the external enclosure by whatever I had the external enclosure set to, too optimistic? Do I need to run some special util to setup the disks in JBOD mode? I guess I thought I only needed to worry about 'special utils' if I was using the disk-pair in a RAID config (0/1)... It seems there should be a linux util to manage the "container", 'sil57xx' -- I take it is not used for RAID-only config? My ultimate aim is to use it in a RAID-0, mirror config (my luck with SATA disk drives has been abysmal, of late (*sigh*)). Anyone with any real-world experience about when the 3Gb SAS starts to become a bottleneck? I know that theoretically, it could support a hair over 350MB/s if there was no overhead, which would reliably only support 2 hard disks at full speed (assuming ~120MB/s max linear read speed/disk). Does that jive with people's real-world experience? I.e. port-multipliers can provide full throughput for 2-HD's but not likely 3? Should I be looking for an sil57xx program somewhere (the box contained a mini-CD, but it looks like a driver for an older kernel (2.6.9). Not so sure about it's usefulness in my setup. Thanks, -linda