From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx15.extmail.prod.ext.phx2.redhat.com [10.5.110.20]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s7OG8OMO007354 for ; Sun, 24 Aug 2014 12:08:24 -0400 Received: from relay4-d.mail.gandi.net (relay4-d.mail.gandi.net [217.70.183.196]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s7OG8Lrb005436 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Sun, 24 Aug 2014 12:08:22 -0400 Received: from mfilter26-d.gandi.net (mfilter26-d.gandi.net [217.70.178.154]) by relay4-d.mail.gandi.net (Postfix) with ESMTP id 97953172094 for ; Sun, 24 Aug 2014 18:08:20 +0200 (CEST) Received: from relay4-d.mail.gandi.net ([217.70.183.196]) by mfilter26-d.gandi.net (mfilter26-d.gandi.net [10.0.15.180]) (amavisd-new, port 10024) with ESMTP id MUgJuwjYq7ZN for ; Sun, 24 Aug 2014 18:08:18 +0200 (CEST) Received: from [10.21.12.10] (meiling.tontut.fi [94.237.68.51]) (Authenticated sender: oranenj@gensoukyou.net) by relay4-d.mail.gandi.net (Postfix) with ESMTPSA id 4999F17208B for ; Sun, 24 Aug 2014 18:08:17 +0200 (CEST) Message-ID: <1408896497.27190.12.camel@kurenai.local> From: Jarkko Oranen Date: Sun, 24 Aug 2014 19:08:17 +0300 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [linux-lvm] Does LVM RAID1 have TRIM support? Reply-To: oranenj+lvm@iki.fi, 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 Hello Yesterday I experimented a bit with my RAID configuration on a pair of SSDs, and it seems that LVM's native RAID does not have TRIM support... At least, when I try to run fstrim manually, it complains even though issue_discards is enabled. Plain LVs on top of an MD RAID PV do work, of course. Am I perhaps missing some configuration, or do RAID1 logical volumes simply not have support for TRIM yet? I'm running a fairly recent kernel (3.15.8) and lvm version says this: LVM version: 2.02.106(2) (2014-04-10) Library version: 1.02.85 (2014-04-10) Driver version: 4.27.0 As an aside, can anyone point me to documentation or other resources about the pros and cons of LVM native RAID1 setup (which I understand uses MD RAID internally?) vs. MD RAID PV + LVM. It seems I might be able to save some SSD space and only mirror the LVs I actually need to keep safe from crashes. -- Jarkko Oranen