From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Robinson Subject: Re: raid1 with rotating offsite disks for backup Date: Thu, 10 Feb 2011 08:43:38 +0000 Message-ID: <4D53A53A.2000409@anonymous.org.uk> References: <1ADCC31C-C4BD-4D43-829F-9341D3663185@stanford.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Roberto Spadim Cc: hansbkk@gmail.com, Jeff Klingner , linux-raid@vger.kernel.org List-Id: linux-raid.ids On 09/02/2011 19:53, Roberto Spadim wrote: > i agree with rsync > rsync is more filesystem related feature > if you want copy files, you should use rsync > if you want to copy the device, may be a dd with devices? > dd if=3D/dev/md0 of=3D/dev/sda > > if you want a snapshot copy, you should first remount your filesystem > to readonly (there=B4s no flock() for /dev/md0 since filesystem don=B4= t > use flock() on /dev/md0) or another way to block writes to filesystem > while you is read from device, some filesystems have online backup > features.. > i don=B4t know lvm very well, but maybe they implement online backup = there... > i don=B4t think it=B4s a problem to solve at md level (it could work,= but > the raid1 purpose is make a fail safe device (or partially safe), not > a online backup device) I do both with several of my customers: md array with LVM on top,=20 suspend system services (mailstore), take snapshot, start system=20 services, then rsync diff the snapshot to another drive with luks=20 crypto, which gets rotated off-site once a week. Generally the backup=20 drives are bigger than the system array, so I can keep at least a week'= s=20 worth of nightlies and several months' worth of weeklies on each one. Yes, I have my own separate securely-stored copies of their crypto keys= =2E Cheers, John. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html