在Linux中将实时文件镜像到NAS

Question

Can anyone tell how I might best mirror selected files and folders to a NAS, (Network Addrssable Storage) box from a Linux workstation in real-time?

These are very large files, (> 50GB) and are being continually modified, so I would only like to change those portions of the files that have been changed, added or deleted.

FYI: These files are actually Virtual Box virtual hard disk (VDI) files.

Answer 1

I discovered that my Synology DS211J NAS can run an RSync service. So I enabled that and used lsyncd for the live mirror... the VirtualBox VMs... all works very well.

Rsync only synchronises the parts of files that have change and so is very efficient at synchronising large files.

Answer 2

Of the solutions that @awm mentioned, only drbd provides block-level, realtime synchronization. The other tools will meet your goal of only propagating deltas, but they operate asynchronously. In fact, rsync will work just as well in this case, since you're not trying to provide bi-directional synchronization.

For drbd to provide block-level replication, you need need to install the drbd kernel modules and userspace tools on both the workstation on the NAS...which means this solution is only appropriate if your NAS is actually a fairly generic Linux box over which you have a great deal of control.

Answer 3

Before hand I just want to suggest that you don't do this. You can easily bottlenet your network and NAS and cause all sorts of problem on your host.

That being said, these claim they can do it: Unison can be found at: http://www.cis.upenn.edu/~bcpierce/unison/ PeerSoft can do it too: http://www.peersoftware.com/products/peersync/peersyncserver/overview.aspx Maybe - http://www.drbd.org/