From owner-freebsd-questions@FreeBSD.ORG Tue Apr 14 18:28:09 2015 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id DDE0374E for ; Tue, 14 Apr 2015 18:28:09 +0000 (UTC) Received: from sender1.zohomail.com (sender1.zohomail.com [74.201.84.162]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id B2810B72 for ; Tue, 14 Apr 2015 18:28:09 +0000 (UTC) Received: from WorkBox.Home (184-100-88-41.mpls.qwest.net [184.100.88.41]) by mx.zohomail.com with SMTPS id 1429036088337692.6387127433926; Tue, 14 Apr 2015 11:28:08 -0700 (PDT) Date: Tue, 14 Apr 2015 13:28:05 -0500 From: Bigby James To: freebsd-questions@freebsd.org Subject: ZFS Volumes, UFS, and TRIM Message-ID: <20150414182805.GA77026@WorkBox.Home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Apr 2015 18:28:10 -0000 Hey folks. I'm having some trouble finding info on a specific ZFS use case: I'm wondering if a ZFS volume on an SSD, formatted to UFS, is covered by native ZFS TRIM support, or if it needs to be enabled on the "embedded" UFS filesystem written to the zvol itself. I see by the man page that by default the OS sees the volume as an ordinary GEOM device, which leads me to infer that TRIM needs to be set using newfs(8) or tunefs(8), but I'm uncertain. Thanks in advance for any help. - Bigby -- "A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools." - Douglas Adams