From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx12.extmail.prod.ext.phx2.redhat.com [10.5.110.17]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r557gvXh003303 for ; Wed, 5 Jun 2013 03:42:57 -0400 Received: from mail-pd0-f170.google.com (mail-pd0-f170.google.com [209.85.192.170]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r557guFE027717 for ; Wed, 5 Jun 2013 03:42:57 -0400 Received: by mail-pd0-f170.google.com with SMTP id x10so1434676pdj.29 for ; Wed, 05 Jun 2013 00:42:56 -0700 (PDT) Received: from gmail.com (nat-pool-pnq-t.redhat.com. [209.132.188.26]) by mx.google.com with ESMTPSA id fm2sm71390907pab.13.2013.06.05.00.42.54 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Wed, 05 Jun 2013 00:42:55 -0700 (PDT) Date: Tue, 4 Jun 2013 22:07:28 -0400 From: Kumar amit mehta Message-ID: <20130605020728.GA9658@gmail.com> MIME-Version: 1.0 Content-Disposition: inline Subject: [linux-lvm] Query on PE size 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" Content-Transfer-Encoding: 7bit To: linux-lvm@redhat.com Hi, I see that a VG will set the default PE size to 4MiB, i.e. 4 * 1024 * 1024 = 4194304 (Please correct me if I'm wrong) # pvcreate /dev/vdc1 # vgcreate testvg /dev/vdc1 # vgdisplay # vgdisplay testvg|grep "PE Size" PE Size 4.00 MiB <---- I see that : vgcreate() -->vgcreate_params_set_defaults() -->vp_def->extent_size = DEFAULT_EXTENT_SIZE * 2; Where DEFAULT_EXTENT_SIZE is #defined to 4096 #define DEFAULT_EXTENT_SIZE 4096 /* In KB */ This means that the default extent size being set is 8192, but as mentioned earlier,the default extent size as reported by 'vgdisplay' is 4 MiB. So Can someone please point me to the place where this conversion of 8192 into 4MiB is taking place in the code ? -Amit