From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Linton Subject: Re: Open/INQUIRY fails on RESERVE'd tape device Date: Fri, 24 Jan 2014 09:36:15 -0600 Message-ID: <52E2886F.3060604@tributary.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from relay.ihostexchange.net ([66.46.182.53]:6119 "EHLO relay.ihostexchange.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752500AbaAXPln (ORCPT ); Fri, 24 Jan 2014 10:41:43 -0500 In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Matthias Eble , "linux-scsi@vger.kernel.org" On 1/23/2014 4:02 PM, Matthias Eble wrote: > So: should open() fail on a reserved tape device? Yes, this is expected behavior for tape devices, reserve 6/release is sometimes used by backup applications in SAN environments as an arbitration mechanism across multiple machines. Its not that the INQUIRY is failing, its that the st open sequence is doing a reserve/TUR/etc during the open. If that fails then you can't open the drives sufficiently to send a inquiry via pass-through. In some environments you can bypass that processing with O_NDELAY/O_NONBLOCK. Or you just use the sg device which doesn't perform the tape open processing that st does.