From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx06.extmail.prod.ext.phx2.redhat.com [10.5.110.30]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t8FGshGo004123 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Tue, 15 Sep 2015 12:54:43 -0400 Received: from mail1.windriver.com (mail1.windriver.com [147.11.146.13]) by mx1.redhat.com (Postfix) with ESMTPS id 299A83B3C7 for ; Tue, 15 Sep 2015 16:54:43 +0000 (UTC) Received: from ALA-HCA.corp.ad.wrs.com (ala-hca.corp.ad.wrs.com [147.11.189.40]) by mail1.windriver.com (8.15.2/8.15.1) with ESMTPS id t8FGsgU3002603 (version=TLSv1 cipher=AES128-SHA bits=128 verify=FAIL) for ; Tue, 15 Sep 2015 09:54:42 -0700 (PDT) Message-ID: <55F84D51.7070400@windriver.com> Date: Tue, 15 Sep 2015 10:54:41 -0600 From: Chris Friesen MIME-Version: 1.0 References: <55F70C58.5010205@windriver.com> <55F71650.7070907@redhat.com> <55F71D24.9010903@windriver.com> <55F7D9A8.5020005@redhat.com> In-Reply-To: <55F7D9A8.5020005@redhat.com> Content-Transfer-Encoding: 7bit Subject: Re: [linux-lvm] Any way to speed up activation of volumes with snapshots? 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"; format="flowed" To: linux-lvm@redhat.com On 09/15/2015 02:41 AM, Zdenek Kabelac wrote: > If you don't mind dropping existing snapshot and creating new 'old-snapshot' - > using larger block size (i.e. 32K (or even more) instead of 4K) may improve > speed of disk reading noticeable (at the price of copying larger chunks when > modifying disk blocks - depends on use-case).... Okay, good info to have. > And if you don't mind replacing your ancient kernel and trying some newer one - > there have been some 'read' order improvement for this old-snapshot target made > as well - so you may at least try if there will be any noticeable change > (actually would be interesting just to get report how much faster it boots when > you only exchange kernel for a boot - you don't have to use it - just measure > boot speed) This is essentially a custom distro, so changing just the kernel is a bit complicated. However, I have a newer version that I want to test with which has a newer kernel but the same version of LVM, so that should give some good data. Chris