From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.11.6/8.11.6) with ESMTP id i94IpIr11777 for ; Mon, 4 Oct 2004 14:51:18 -0400 Received: from mproxy.gmail.com (rproxy.gmail.com [64.233.170.196]) by mx3.redhat.com (8.12.11/8.12.10) with ESMTP id i94IpCjP029621 for ; Mon, 4 Oct 2004 14:51:13 -0400 Received: by mproxy.gmail.com with SMTP id v18so3688759rnb for ; Mon, 04 Oct 2004 11:51:12 -0700 (PDT) Message-ID: Date: Mon, 4 Oct 2004 11:51:12 -0700 From: L Dong Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [linux-lvm] snapshot performance Reply-To: L Dong , 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, I'm using LVM1 on 2.4.18 without any problem. However, after I take a snapshot of a volume, the write performance to the original volume is degraded by about 5 times. Why such a big degrade? Moreover, I expect only the first time write should involve copying the original data block. So the later write operations into the original volume should not have performance degradation. However, this is not true. The latter writes are also very slow. Should I upgrade to DM and LVM2? Will this improve snapshot performance? Thanks for any help.