I've just spent some time quickly researching this to no real satisfaction.
What I'm looking for is a way to do real-time hot-replication of a whole filesystem or filesystem tree over 2 nodes (and strictly 2 nodes) without STOMITH[1].
The scenario is I have two identical systems with local (software) RAID1. They will be tethered onto their internet feed via ethernet, and can optionally be tethered to each other via Gig.
I want to be able to set it up so /home (and maybe other filesystems) are replicated from one to the other, in both directions, in real time so they can run in an all-hot redundant cluster.
The environment should be mostly read-oriented, so I can live with write-latent solutions as long as they handle the race/collision gracefully (preferably by actually detecting and reporting it if they can't avoid it).
The options I've investigated so far: * Lustre (MDS requirements[2] make this not an option) * GlobalFS (STOMITH requirements make this not an option. Oriented towards shared media too, which I am not using) * tsync (Naive concurrent operation model, but otherwise viable) * MogileFS (not quite what I was looking for, but none the less useful). * OpenAFS (read-only replication only, loss of the node hosting the write volume still renders the volume unwritable). Is anybody aware of any other options that I've missed? C. [1] "Shoot The Other Machine In The Head" - the ability for any node to forcibly powerdown any other node believed to be malfunctioning. [2] Single instance MDS only, only clusterable through shared storage. d'oh. [3] People suggesting rsync will be taken out back and shot for not reading the requirements. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html