From mboxrd@z Thu Jan 1 00:00:00 1970 From: andy liebman Subject: Real Time Mirroring of a NAS Date: Fri, 07 Apr 2006 06:47:18 -0400 Message-ID: <44364336.7060704@aol.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi, I'm looking for a way to create a real-time mirror of a NAS. In other words, say I have a 5.5 TB NAS (3ware 16-drive array, RAID-5, 500 GB drives). I want to mirror it in real time to a completely separate 5.5 TB NAS. RSYNCing in the background is not an option. The two NAS boxes need to hold identical data at all times. It is NOT necessary that the data be accessed from both NAS boxes simultaneously. One is simply a backup of the other. I guess one option might be to use Redhat's Global File System (GFS). Although there seems to be an 8TB limit for a GFS filesystem, which could be an issue down the road. But would the following approach work: Can I export NAS B as a SAN or ISCSI target, connect the two machines with, say, mryinet cards or 10 GbE TOE cards, mount the NAS B volume on NAS A, and create a RAID-1 mirror of the two volumes? Is this kind of thing done? Andy Liebman