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[SLUG] Network Real-Time Hot Filesystem Replication?
- To: slug@xxxxxxxxxxx
- Subject: [SLUG] Network Real-Time Hot Filesystem Replication?
- From: Crossfire <xfire@xxxxxxxx>
- Date: Sat, 05 Apr 2008 09:52:55 +1100
- User-agent: Thunderbird 220.127.116.11 (Windows/20080213)
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)
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 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?
 "Shoot The Other Machine In The Head" - the ability for any node to
forcibly powerdown any other node believed to be malfunctioning.
 Single instance MDS only, only clusterable through shared storage.
 People suggesting rsync will be taken out back and shot for not
reading the requirements.