From owner-freebsd-fs@FreeBSD.ORG Wed Jul 3 19:39:31 2013 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 27225242 for ; Wed, 3 Jul 2013 19:39:31 +0000 (UTC) (envelope-from berend@pobox.com) Received: from smtp.pobox.com (b-pb-sasl-quonix.pobox.com [208.72.237.35]) by mx1.freebsd.org (Postfix) with ESMTP id E423211B8 for ; Wed, 3 Jul 2013 19:39:30 +0000 (UTC) Received: from smtp.pobox.com (unknown [127.0.0.1]) by b-sasl-quonix.pobox.com (Postfix) with ESMTP id C3E6F2D4A4; Wed, 3 Jul 2013 19:39:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=date :message-id:from:to:cc:subject:in-reply-to:references :mime-version:content-type:content-transfer-encoding; s=sasl; bh=F+9mwqDN+fTkz2QgWiIpvEtrfzQ=; b=o52CRUr1zfNsf4rmu5jEb1ZwSdO8 +tptMpJCsDwiCQAgmIBLMcTPpq4pfPZzCFqsMXliLS5LvtwNd+xRRrTupTpPXJTZ YcoamxyqIXAyyDL8li0aoI2eRlIH8FpWfXOnzCtuqIYFy4jkcy03c/3RVGvCtO8f iPVrlyaHTnaHuBE= DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=date:message-id :from:to:cc:subject:in-reply-to:references:mime-version :content-type:content-transfer-encoding; q=dns; s=sasl; b=Vcx2es cgwvSXzafRe1o/gHqHN9s4BBxnQXthlNTpTC/us+F/FQTpV9tuiEHruhtGAb+KJg sBGZv8U3V/s2Tc/fhaH7K7mIHm7ZRAzmdFb7aAc9k3EbrzSie+ZcuYY/lKILwV6S NYze11LFNouAcemlq39eHVB/cAOo4JcuiiPsA= Received: from b-pb-sasl-quonix.pobox.com (unknown [127.0.0.1]) by b-sasl-quonix.pobox.com (Postfix) with ESMTP id BA8B92D4A3; Wed, 3 Jul 2013 19:39:29 +0000 (UTC) Received: from bmach.nederware.nl (unknown [27.252.247.84]) by b-sasl-quonix.pobox.com (Postfix) with ESMTPA id 749F52D49B; Wed, 3 Jul 2013 19:39:28 +0000 (UTC) Received: from quadrio.nederware.nl (quadrio.nederware.nl [192.168.33.13]) by bmach.nederware.nl (Postfix) with ESMTP id 8D8EF5C55; Thu, 4 Jul 2013 07:39:21 +1200 (NZST) Received: from quadrio.nederware.nl (quadrio.nederware.nl [127.0.0.1]) by quadrio.nederware.nl (Postfix) with ESMTP id 3090E4A11BF3; Thu, 4 Jul 2013 07:39:26 +1200 (NZST) Date: Thu, 04 Jul 2013 07:39:26 +1200 Message-ID: <87mwq34emp.wl%berend@pobox.com> From: Berend de Boer To: "Mark Felder" Subject: Re: EBS snapshot backups from a FreeBSD zfs file system: zpool freeze? In-Reply-To: References: <87li5o5tz2.wl%berend@pobox.com> <87ehbg5raq.wl%berend@pobox.com> <20130703055047.GA54853@icarus.home.lan> <6488DECC-2455-4E92-B432-C39490D18484@dragondata.com> <871u7g57rl.wl%berend@pobox.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 EasyPG/1.0.0 Emacs/24.3 (i686-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) Organization: Xplain Technology Ltd MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: multipart/signed; boundary="pgp-sign-Multipart_Thu_Jul__4_07:39:25_2013-1"; micalg=pgp-sha256; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit X-Pobox-Relay-ID: 46551D48-E418-11E2-9C99-E84251E3A03C-48001098!b-pb-sasl-quonix.pobox.com Cc: freebsd-fs X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 03 Jul 2013 19:39:31 -0000 --pgp-sign-Multipart_Thu_Jul__4_07:39:25_2013-1 Content-Type: text/plain; charset=US-ASCII >>>>> "Mark" == Mark Felder writes: Mark> On the other hand, every time I read about "block storage Mark> snapshots" -- even if you quiesce the filesystem -- I start Mark> to get really itchy thinking about the likeliness a high TPS Mark> database is going to end up with corruption and require Mark> recovery. :) That's not how it works: if you freeze the file system at a consistent point, you can use the roll-forward/backward capabilities of your db to come back clean. You can do this even fancier. Mysql or Mongo allow you to flush their caches as well + put in place a global lock of the database. Then you freeze the file system, take the snapshot, unfreeze file system, then unfreeze mysql. People have been using this for many years, for example a famous utility for this was mylvmbackup: http://www.lenzg.net/mylvmbackup/ ZFS should work really well here, and people probably use zfs snapshots in this manner. If performance is an issue, you do this on the slave obviously. But I don't get the itchy part: if a disk is just software, I can copy it. I want to copy it. To another data centre (zone) for example. That's a trivial operation in EBS, and you can clone huge disks this way in minutes. Doing an zfs send/recv is just laughably primitive and slow compared to this. It would take me days to send a full snapshot this way. Mark> This really does sound like Amazon needs to provide whatever Mark> mechanism to communicate between the host and the guest so Mark> this EBS snapshot can take place. Again, my request has *nothing* to do with EBS. If you have multiple disks in your pool, how can you make a backup you can restore from, at the hardware level. -- All the best, Berend de Boer ------------------------------------------------------ Awesome Drupal hosting: https://www.xplainhosting.com/ --pgp-sign-Multipart_Thu_Jul__4_07:39:25_2013-1 Content-Type: application/pgp-signature Content-Transfer-Encoding: 7bit Content-Description: OpenPGP Digital Signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (GNU/Linux) iQIcBAABCAAGBQJR1H3tAAoJEKOfeD48G3g5ql8P/3bHdabY6NmGUkoNma2liHqV UcXJaoBzE6CbYtqI/evR/ZNfLLX5MK9wChdRV4dlVbAVMzpo7u/9+i8J68WDyoS8 hyUQjHVWJ8o50eblblRIxWf1hUrimGGQ5T5xVXvrEZTSmyvsMWAsNZAs12gk5YHI McTvXFkDmEefRzPQiIymY0tjRzASDiNX8daBbkYefxcGJU7CMQBbufAdvonlxXdB J0PIwxyFH3YyUJ52YoET0WOWnU3//A9+R8NNYDrISd3gG0bxAD7xLcenK3dqR+lY mt2pJhccltLHtVuC52nUnxkCO+CtuXOWGRdO0pbJO0LIDOoGC0lVCNcl14jQYcF3 bRwC7E7vs0EbNTSJYdjr2RuUIbLUM04Qn83r4xnmAN9zBdTeZzG3a4bFcpjMw+Ij gSdCFmlHokSaYs0m2ccy0FocueIMZjjT2lJFHWSign3GCYrewceHJqkoLrTVDkQY EPPRPS0Fre7v1jLyH2ozURksIpAWfkWmXZtBTvvPhhVLr1XS0hbMEIWZA4kyoPip lRBT4kTwyJWu69h9i3XWNxy6herrb9AUoC2MFMESbTqDo/DFbzTz4X2O4ZOm4F8v b5UamlMD6odeCrslNywoc8zp86qlK/gBGQ7Xybxa8XEyGLfh/VCwhqsOpXSKBz/j of+vLR4aCPV9BkeTGr73 =5+03 -----END PGP SIGNATURE----- --pgp-sign-Multipart_Thu_Jul__4_07:39:25_2013-1--