From owner-freebsd-questions@freebsd.org Wed Oct 21 00:33:17 2015 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 807C4A1A8ED for ; Wed, 21 Oct 2015 00:33:17 +0000 (UTC) (envelope-from brandon.wandersee@gmail.com) Received: from mail-ig0-f176.google.com (mail-ig0-f176.google.com [209.85.213.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 57A06C72 for ; Wed, 21 Oct 2015 00:33:16 +0000 (UTC) (envelope-from brandon.wandersee@gmail.com) Received: by igbkq10 with SMTP id kq10so87545065igb.0 for ; Tue, 20 Oct 2015 17:33:16 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=from:to:subject:date:message-id:mime-version:content-type; bh=464nt15bH9+paYHL9whDu/DoYBnZt9V6/eACfKgcX7A=; b=ZX1ril82FdwgEPZxpH8NIC9A6AnBs00E4vO7/xOoEN1Y82Mm5yW6m49Iwxg2i2c/vU Rqe5cojdlN+YqGT0cYfOwvp9Q6JVTEr4Gdp3Fl1bFkT/OMW6hw3SHiz+YSnmhg5qPl7x CmENgdZj7eXQStS4siix29raXEVYtd9FzTg6YyPImkoBlNMEVtmcrkMtiIFisUBs+2f9 0JxyvlyTytMT4GsZ4Gm7Qi75qz0nBhlfkiObJ/jGaoThkVZAvByHNDgwm+sTZp9dbMWM bM4CzQI7ZruQgyS0AlxFKPqPvLXkRdoUKfxjkcDiI/yVvXVlLqYBTSWjwqt4teX6nZBg bBaA== X-Received: by 10.50.20.135 with SMTP id n7mr7774381ige.4.1445387595922; Tue, 20 Oct 2015 17:33:15 -0700 (PDT) Received: from WorkBox.Home.gmail.com (63-231-132-20.mpls.qwest.net. [63.231.132.20]) by smtp.gmail.com with ESMTPSA id pi6sm10965287igb.21.2015.10.20.17.33.14 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 20 Oct 2015 17:33:15 -0700 (PDT) From: Brandon J. Wandersee To: freebsd-questions@freebsd.org Subject: gjournal and TRIM: A safe combination? Date: Tue, 20 Oct 2015 19:33:13 -0500 Message-ID: <867fmh12nq.fsf@WorkBox.Home> MIME-Version: 1.0 Content-Type: text/plain 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: Wed, 21 Oct 2015 00:33:17 -0000 I've recently created several new UFS partitions on an SSD. I activated gjournal on the largest--about 200Gb in size--and afterward received a warning during boot-up: WARNING: /usr/home: TRIM flag on fs but disk does not confirm that it supports TRIM The disk does indeed support TRIM, and `camcontrol identify` can detect as much, but it seems gjrounal interferes with this detection. But does it actually interfere with TRIM in any way? More importantly, does it endanger the data on the filesystem at all? The real issue, I suppose, is that there are four possible formatting options: 1. UFS with TRIM, but without journaling. Disk performance is maintained, but data is unprotected in the event of a crash. 2. UFS with journaling, but without TRIM. Data is likely protected should a crash occur, but the filesystems need to be periodically recreated with `newfs -E`to restore performance. 4. UFS with both journaling and TRIM. Ideal, so long as one doesn't interfere with the other. 3. UFS with neither journaling or TRIM. Not an option. I guess I'm just curious which of the first three I should go for. Daily backups are part of my routine in any case. Thanks in advance for any advice or clarification. -- ================================================================== :: Brandon Wandersee :: :: brandon.wandersee@gmail.com :: ================================================================== 'A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.' - Douglas Adams ==================================================================