Realtime Filesystem Replication
wmoran at potentialtech.com
Tue May 6 12:06:36 PDT 2003
> Thanks so far to the suggestions including rsync and unison. Both appear
> to be triggered upon a command line or user typed command. Is someone
> using a system that tracks the mtimes for files and updates without
Are you sure you really need _realtime_? That's a pretty tall order, and
I don't know of anything that can provide it.
OTOH, with rsync as a cron job, you can easily mirror a large amount of
data, say, every 5 minutes. If a 5-minute lag in data replication is
acceptable, I would recommend using rsync instead of looking for something
more "real time". I don't know if any true "real time" synchronizing
Let me ask you a few questions: 1. What is the maximum acceptable "lag" for
data replication? 2. How much data do you estimate there will be? (both
megs and # of files) 3. How often do you estimate the data will change?
If 1 is longer than a few minutes, and 2 and 3 aren't terribly demanding,
rsync is probably the way to go.
On a related note: I had an idea that you should be able to create some
sort of network RAID using the new GEOM system. Something that would allow
everything that was written to a local filsystem to also be mirrored via
NFS to another system. I haven't had a chance to do anything more than
dream about it, though.
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