From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx08.extmail.prod.ext.phx2.redhat.com [10.5.110.32]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E6D027BCC3 for ; Mon, 10 Apr 2017 14:19:44 +0000 (UTC) Received: from mail-wr0-f173.google.com (mail-wr0-f173.google.com [209.85.128.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id CD257C059747 for ; Mon, 10 Apr 2017 14:19:42 +0000 (UTC) Received: by mail-wr0-f173.google.com with SMTP id z109so9994532wrb.1 for ; Mon, 10 Apr 2017 07:19:42 -0700 (PDT) References: <2048a92a-0505-78c3-da00-8bf2043f4cbf@yahoo.co.uk> <38e06f2a-5af9-6469-ec2c-5bde2c1b199b@gmail.com> <3e790d03-8da8-13c4-d1d3-e1f5f7b3c6f9@yahoo.co.uk> From: Zdenek Kabelac Message-ID: <18cefd41-2c11-5655-a117-2572b1bc4b7a@gmail.com> Date: Mon, 10 Apr 2017 16:19:40 +0200 MIME-Version: 1.0 In-Reply-To: <3e790d03-8da8-13c4-d1d3-e1f5f7b3c6f9@yahoo.co.uk> Content-Transfer-Encoding: 7bit Subject: Re: [linux-lvm] stripped LV with segments vs one segment 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: lejeczek , LVM general discussion and development Dne 10.4.2017 v 13:16 lejeczek napsal(a): > > > On 10/04/17 12:03, Zdenek Kabelac wrote: >> Dne 10.4.2017 v 11:29 lejeczek napsal(a): >>> hi there >>> >>> I could not extend my stripped LV, had 3 stripes and wanted to add one more. >>> Only way LVM let me do it was where I ended up with this: >>> >>> --- Segments --- >>> Logical extents 0 to 751169: >>> Type striped >>> Stripes 3 >>> Stripe size 16.00 KiB >>> Stripe 0: >>> Physical volume /dev/sdd >>> Physical extents 0 to 250389 >>> Stripe 1: >>> Physical volume /dev/sde >>> Physical extents 0 to 250389 >>> Stripe 2: >>> Physical volume /dev/sdc >>> Physical extents 0 to 250389 >>> >>> Logical extents 751170 to 1001559: >>> Type linear >>> Physical volume /dev/sdf >>> Physical extents 0 to 250389 >>> >>> 1st question - was this really the only way LVM would extend? >>> 2nd - is there performance penalty with segments like above vs one stripped >>> segment? >>> >> >> Hi >> >> >> Not really sure what you aim to do. >> >> If you have LV segment with 3 stripes - you have to keep also extension >> using 3 stripes - you can't have 1st. halve of LV spanning 3 disk and add >> there a new LV segment as linear - as listed in this post. >> >> Both segments must by striped. >> >> Regards >> >> Zdenek > > I had 3 stripe LV, you know, three PVs, and wanted the LV to have 4 stripes, > wanted to add 4th PV, you can see it from above lvdisplay. > I tried these and each time it errored: > $ lvextend -v -i 4 -l+100%free dellH200.InternalB/0 > $ lvextend -v -i 4 -l+100%pv dellH200.InternalB/0 /dev/sdf You can't request stripe 4 (needs 4 disks) and pass just single /dev/sdf device. Zdenek