From owner-freebsd-questions@FreeBSD.ORG Sun Mar 25 19:49:39 2012 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id AEFB6106564A for ; Sun, 25 Mar 2012 19:49:39 +0000 (UTC) (envelope-from dpchrist@holgerdanske.com) Received: from holgerdanske.com (holgerdanske.com [IPv6:2001:470:0:19b::b869:801b]) by mx1.freebsd.org (Postfix) with SMTP id 9A66B8FC18 for ; Sun, 25 Mar 2012 19:49:39 +0000 (UTC) Received: from ::ffff:69.12.202.165 ([69.12.202.165]) by holgerdanske.com for ; Sun, 25 Mar 2012 12:49:32 -0700 Message-ID: <4F6F76CC.7030300@holgerdanske.com> Date: Sun, 25 Mar 2012 12:49:32 -0700 From: David Christensen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.16) Gecko/20120207 Icedove/3.0.11 MIME-Version: 1.0 To: freebsd-questions@freebsd.org Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: LUKS/ dm-crypt/ ext4 appears to be single threaded X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 25 Mar 2012 19:49:39 -0000 freebsd-questions: Thread moved from debian-user and dm-crypt. http://lists.debian.org/debian-user/2012/03/msg01154.html http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/5724 I seem to recall FreeBSD having encrypted disks/ filesystems/ whatever. Is there one that is multi-threaded? TIA, David I have a 1.5 TB SATA hard drive I use for back-up's. It has a single large partition encrypted with LUKS/ dm-crypt and formatted with ext4. I've noticed what appears to be single-threaded behavior when one process is performing a long-lived write to the disk (notably 'ssh user@host tar ... > backupfile.tar.gz') and another process attempts to access the disk (either read or write). This is tolerable for a back-up application, but would not be acceptable for multi-user, multi-process, and/or multi-threaded applications (file server, terminal server, web server, etc.). Is this a fundamental limitation of LUKS, dm-crypt, and/or ext4, or something I've configured/ misconfigured? If a fundamental limitation, is there something I can substitute to eliminate the problem? Some manufacturers make hard drives with built-in encryption. Are these supported by Debian, Linux, or BSD? http://www.seagate.com/www/en-us/products/self-encrypting-drives/ Any other comments or suggestions? TIA, David