From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx14.extmail.prod.ext.phx2.redhat.com [10.5.110.19]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id q1GDoItr024721 for ; Thu, 16 Feb 2012 08:50:18 -0500 Received: from mail-bk0-f46.google.com (mail-bk0-f46.google.com [209.85.214.46]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q1GDo90r010557 for ; Thu, 16 Feb 2012 08:50:10 -0500 Received: by bkcjm19 with SMTP id jm19so2766960bkc.33 for ; Thu, 16 Feb 2012 05:50:09 -0800 (PST) Message-ID: <4F3D098F.4010709@profitbricks.com> Date: Thu, 16 Feb 2012 14:50:07 +0100 From: Sebastian Riemer MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [linux-lvm] Allocation Policy for Cloud Computing needed Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: linux-lvm@redhat.com Hi LVM list, I'm experimenting with storage for many QEMU/KVM virtual machines in cloud computing. I've got many concurrent IO processes and 24 hard drives. I've tested the scalability with a single IO reader process per hard drive. Single drives scale best and have the best performance of cause, but we need mirroring and volume management. So I've created MD RAID-1 arrays and created on each a VG and two LVs. This gives me good overall performance (up to 2 GB/s, HBA limit: 2.2 GB/s). Then, I've tested to put all my RAID-1 arrays into a single VG, because LV size should be adjustable over all hard drives. I've tried all allocation policies but none does what I want to achieve here. Yeah, that this isn't implemented fully is in the man page, ... . I want to have an allocation which distributes the LVs equally over the PVs as long as space is left and LVs aren't resized. The goal is to minimize the number of concurrent IO processes per hard drive (striping is total crap in this situation). I've tested LVM2 2.02.66 and kernel 3.0.15. Is something like that implemented in newer releases or is something like that intended to be implemented in near future? Or does someone want to implement this together with me? Thanks, cheers, Sebastian -- Sebastian Riemer Linux Kernel Developer ProfitBricks GmbH Greifswalder Str. 207 10405 Berlin, Germany Tel.: +49 - 30 - 60 98 56 991 - 303 Fax: +49 - 30 - 51 64 09 22 Email: sebastian.riemer@profitbricks.com Web: http://www.profitbricks.com/ RG: Amtsgericht Charlottenburg, HRB 125506 B GF: Andreas Gauger, Achim Weiss