From owner-freebsd-stable@FreeBSD.ORG Thu Apr 28 20:45:34 2011 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id C813C1065670 for ; Thu, 28 Apr 2011 20:45:34 +0000 (UTC) (envelope-from mwaltz@PACIFIC.EDU) Received: from mx10.pacific.edu (mx10.pacific.edu [138.9.240.95]) by mx1.freebsd.org (Postfix) with ESMTP id 9B3FB8FC17 for ; Thu, 28 Apr 2011 20:45:34 +0000 (UTC) Received: from mx10.pacific.edu (localhost [127.0.0.1]) by localhost (Postfix) with SMTP id 39710A49E50; Thu, 28 Apr 2011 13:45:34 -0700 (PDT) Received: from EXCASHUB1.stk.pacific.edu (excashub1.stk.pacific.edu [10.9.4.121]) by mx10.pacific.edu (Postfix) with ESMTP id F2893A49D04; Thu, 28 Apr 2011 13:45:33 -0700 (PDT) Received: from EXMB2.STK.PACIFIC.EDU ([10.9.4.102]) by excashub1.stk.pacific.edu ([10.9.4.121]) with mapi id 14.01.0289.001; Thu, 28 Apr 2011 13:45:34 -0700 From: Malcolm Waltz To: Chuck Swiger Thread-Topic: ZFS vs OSX Time Machine Thread-Index: AQHMBa0X6h4oagP/h0u8OmOQbCHfSJR0DWwAgAAOYwCAAARggIAAFD+A Date: Thu, 28 Apr 2011 20:45:33 +0000 Message-ID: References: <537A8F4F-A302-40F9-92DF-403388D99B4B@gsoft.com.au> <2B80846C-E8A9-4FF6-962C-9405469661D6@mac.com> <8D2285F1-3706-4FEB-A4B4-10089AC7A622@mac.com> In-Reply-To: <8D2285F1-3706-4FEB-A4B4-10089AC7A622@mac.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.9.104.200] Content-Type: text/plain; charset="us-ascii" Content-ID: <39424AA978AA2840B5B855915326F3A7@pacific.local> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-PMX-Version: 5.6.0.2009776, Antispam-Engine: 2.7.2.376379, Antispam-Data: 2011.4.28.203318 X-PerlMx-Spam: Gauge=IIIIIIII, Probability=8%, Report=' SUPERLONG_LINE 0.05, BODYTEXTP_SIZE_3000_LESS 0, BODY_SIZE_2000_2999 0, BODY_SIZE_5000_LESS 0, BODY_SIZE_7000_LESS 0, FROM_EDU_TLD 0, WEBMAIL_SOURCE 0, WEBMAIL_XOIP 0, WEBMAIL_X_IP_HDR 0, __BOUNCE_CHALLENGE_SUBJ 0, __BOUNCE_NDR_SUBJ_EXEMPT 0, __CANPHARM_UNSUB_LINK 0, __CP_MEDIA_BODY 0, __CP_URI_IN_BODY 0, __CT 0, __CTE 0, __CT_TEXT_PLAIN 0, __HAS_MSGID 0, __HAS_XOIP 0, __LINES_OF_YELLING 0, __MIME_TEXT_ONLY 0, __MIME_VERSION 0, __MSGID_APPLEMAIL 0, __PHISH_SPEAR_STRUCTURE_1 0, __SANE_MSGID 0, __TO_MALFORMED_2 0, __URI_NO_WWW 0, __URI_NS ' Cc: FreeBSD Stable Subject: Re: ZFS vs OSX Time Machine X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Apr 2011 20:45:35 -0000 AFP is not the same as HFS+. Time Machine will work better with AFP than N= FS or SMB/CIFS, but it's still not using native HFS+ unless you are using b= lock storage (even if you use AFP with an HFS+ filesystem). Time Machine cannot function at all without accessing HFS+ directly. If yo= u are using a network filesystem (AFP, SMB/CIFS or NFS), Time Machine creat= es a sparse disk image, formatted as HFS+ and stores it on your file-server= . It then attaches that disk image as a disk device and mounts it (somewha= t like "mdconfig -a -t vnode -f /path/to/disk-image -u 1; mount /dev/md1 /m= nt"). It then treats that disk image basically the same way that it treats= local attached storage, including creating hard directory links (but all i= nside the disk image). See man hdiutil (on OS X) for more info, particular= ly the part about SPARSEBUNDLEs, sparse images backing HFS+ filesystems and= band sizes. Even if you use Mac OS 10 Server and create a Time Machine share (which is = the best case scenario), it still uses emulated block storage as described = above (disk image over AFP on HFS+). I have personally done this and decid= ed that it was not a very good solution. Your milage may very. I know tha= t people do this, but it seems rather silly. If you have the knowledge to use ZFS, use a zvol via iSCSI. It is much mor= e efficient to use a form of network storage that handles block access nati= vely (like iSCSI) instead of accessing emulated block storage via file-shar= ing protocols that were not designed for such use. ZFS doesn't care what y= ou use it for. If you are using ZFSv28 (I wouldn't use it for critical dat= a on FreeBSD yet) you can even do dedupe and compression on a native HFS+ T= ime Machine volume (although you would only see the saved space from the pe= rspective of the zpool and make sure you have lots of RAM).=20 On Apr 28, 2011, at 12:33 PM, Chuck Swiger wrote: > On Apr 28, 2011, at 12:17 PM, George Kontostanos wrote: >> I am using TM over smb on a ZFS Raidz1 pool of my fileserver with no pro= blems whatsoever. =20 >>=20 >> NAME USED AVAIL REFER MOUNTPOINT >> tank/apple 37.2G 82.8G 37.2G /tank/apple >>=20 >> Oldest backup 14 December 2009 >=20 > SMB aka CIFS is a better choice than NFS, because it supports better lock= ing (oplocks or "stealable" locks), but it is not as good as AFP for this p= articular purpose. Also, ZFS isn't going to be as space efficient at stori= ng TM backups compared with HFS+, because it doesn't support hard links to = directories. >=20 > Regards, > --=20 > -Chuck >=20 >=20 >=20 > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org"