From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Ujval Lodha" Subject: Writing to tape from C system calls Date: Fri, 12 Dec 2003 20:39:06 +0800 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <035701c3c0ac$f1ccbae0$aa00a8c0@ASTERIX> References: <033701c3c0ac$97659270$aa00a8c0@ASTERIX> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from [203.132.205.66] ([203.132.205.66]:56544 "EHLO helium.gdc-tech.com") by vger.kernel.org with ESMTP id S264556AbTLLMjR (ORCPT ); Fri, 12 Dec 2003 07:39:17 -0500 Received: from ASTERIX ([192.168.0.170]) (authenticated) by helium.gdc-tech.com (8.11.6/8.11.0) with ESMTP id hBCCZSa15989 for ; Fri, 12 Dec 2003 20:35:29 +0800 List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org Hi I'm new to tape devices. My application requires me to seek to a certain block on the tape device and write data on it (besides being able to retrieve data by reading). So far, I have no trouble reading from the tape. When I write to it at any block that block becomes the last block on the device. I am unable to seek to any block after that on the tape. I have tried : a. Using mt to seek and dd to write b. Using open / ioctl / write from C Both with the same results. I am using a Tandberg SDLT for my tests with the linux kernel st drivers. Is this normal? Is it not possible to use the tape device - and modify data at any block by seeking to it and writing? Is there some source of information where I can read about programming tape devices from C? So far, I havent been able to find one. Please advise. Regards, Ujval Lodha