From owner-freebsd-questions@freebsd.org Thu Sep 24 12:52:44 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 1BEA6A08D03 for ; Thu, 24 Sep 2015 12:52:44 +0000 (UTC) (envelope-from raimund.sacherer@logitravel.com) Received: from formentor.toolfactory.net (pina.toolfactory.net [213.97.158.39]) by mx1.freebsd.org (Postfix) with ESMTP id B7D0211D9 for ; Thu, 24 Sep 2015 12:52:43 +0000 (UTC) (envelope-from raimund.sacherer@logitravel.com) Received: from localhost (localhost.localdomain [127.0.0.1]) by formentor.toolfactory.net (Postfix) with ESMTP id 712C01786EE for ; Thu, 24 Sep 2015 14:42:42 +0200 (CEST) Received: from formentor.toolfactory.net ([127.0.0.1]) by localhost (formentor.toolfactory.net [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id Ll_Az9uZ_b9Q for ; Thu, 24 Sep 2015 14:42:42 +0200 (CEST) Received: from localhost (localhost.localdomain [127.0.0.1]) by formentor.toolfactory.net (Postfix) with ESMTP id 07F5A1786ED for ; Thu, 24 Sep 2015 14:42:42 +0200 (CEST) X-Virus-Scanned: amavisd-new at logpmzimmta01v.toolfactory.net Received: from formentor.toolfactory.net ([127.0.0.1]) by localhost (formentor.toolfactory.net [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id vI8znpZze_fJ for ; Thu, 24 Sep 2015 14:42:41 +0200 (CEST) Received: from xorrigo.toolfactory.net (xorrigo.toolfactory.net [192.168.2.210]) by formentor.toolfactory.net (Postfix) with ESMTP id E4D221786E2 for ; Thu, 24 Sep 2015 14:42:41 +0200 (CEST) Date: Thu, 24 Sep 2015 14:42:41 +0200 (CEST) From: Raimund Sacherer Reply-To: Raimund Sacherer To: FreeBSD Questions Message-ID: <480627999.9462316.1443098561442.JavaMail.zimbra@logitravel.com> In-Reply-To: <1059990807.9456607.1443097747193.JavaMail.zimbra@logitravel.com> Subject: Restructure a ZFS Pool MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.2.213] X-Mailer: Zimbra 8.0.8_GA_6184 (ZimbraWebClient - SAF7 (Mac)/8.0.8_GA_6184) Thread-Topic: Restructure a ZFS Pool Thread-Index: rucbOPvwfEmoBa+0XQ6LmkN/GW7+5w== 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: Thu, 24 Sep 2015 12:52:44 -0000 Hello, I have a ZFS pool consisting of 12 4TB drives, where 2 of those drives are dedicated as spares, as this was my first FreeBSD / ZFS server I did some things different than I would do it know and I want to rectify them: # zpool status pool: tank state: ONLINE scan: scrub repaired 0 in 58h52m with 0 errors on Thu Sep 24 02:29:47 2015 config: NAME STATE READ WRITE CKSUM tank ONLINE 0 0 0 raidz1-0 ONLINE 0 0 0 da0 ONLINE 0 0 0 da1 ONLINE 0 0 0 da2 ONLINE 0 0 0 da3 ONLINE 0 0 0 da4 ONLINE 0 0 0 da5 ONLINE 0 0 0 da6 ONLINE 0 0 0 da7 ONLINE 0 0 0 da8 ONLINE 0 0 0 da9 ONLINE 0 0 0 spares da10 AVAIL da11 AVAIL errors: No known data errors I had the pool fill up to over 80%, then I got it back to about 50-60%, but it feels more sluggish. I use a lot of NFS and we use it to backup some 5 million files in lots of sub-directorys (a/b/c/d/abcd...), besides other big files (SQL dump backups, bacula, etc.) I said above sluggish because I do not have empirical data and I do not know exactly how to test the system correctly, but I read a lot and there seem to be suggestions that if you have NFS etc. that a independent ZIL helps with copy-on-write fragmentation. What I would like to know is if I can eliminate one Spare disk from the pool, and add it as a ZIL again, without having to shutdown/reboot the server? I am also thinking about swapping the spare 4TB disk for a small SSD, but that's immaterial to whether I can perform the change. Also I would appreciate it if someone has some pointers on how to test correctly so I see if there are real benefits before/after this operation. Thank you, Best Ray