From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurence Oberman Subject: All scsi_debug devices in the scsi_debug driver share the same RAM space Date: Sat, 03 Feb 2018 14:43:12 -0500 Message-ID: <1517686992.18584.8.camel@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-qk0-f182.google.com ([209.85.220.182]:37166 "EHLO mail-qk0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752026AbeBCTnQ (ORCPT ); Sat, 3 Feb 2018 14:43:16 -0500 Received: by mail-qk0-f182.google.com with SMTP id z65so365712qka.4 for ; Sat, 03 Feb 2018 11:43:16 -0800 (PST) Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: dgilbert , linux-scsi@vger.kernel.org, Bart Van Assche Cc: John Pittman , Jon Magrini Hello Doug I had emailed you earlier about this issue forgetting to copy others. All test devices in the scsi_debug driver share the same ram space so we cannot really have individual devices for testing stuff like md- raid. I bumped into this a few times already and I think it would be useful to make each device an individual RAM entry so we can create multiple unique devices. Of course this means also now having to maybe start using attributes for each device do we can selectively choose which devices get the fault injections. I know its adding complexity here but wanted to get input about the possibility of changing this. For a particular fault injection case this morning I had to use 5 regular drives and 1 scsi-debug drive to inject faults to reproduce an md-raid issue. I also wanted a different start sector and range and sent an earlier patch for that. So is this something worth considering ? If so, i will start working on it. Regards Laurence