If you are on 0.6, repair is particularly dangerous with respect to disk space usage. If your replica is sufficiently out of sync, you can triple your disk usage pretty easily. This has been improved in 0.7, so repairs should use about half as much disk space, on average.
In general, yes, keep your nodes under 50% disk usage at all times. Any of: compaction, cleanup, snapshotting, repair, or bootstrapping (the latter two are improved in 0.7) can double your disk usage temporarily. You should plan to add more disk space or add nodes when you get close to this limit. Once you go over 50%, it's more difficult to add nodes, at least in 0.6. - Tyler On Thu, Dec 9, 2010 at 11:19 AM, Mark <static.void....@gmail.com> wrote: > I recently ran into a problem during a repair operation where my nodes > completely ran out of space and my whole cluster was... well, clusterfucked. > > I want to make sure how to prevent this problem in the future. > > Should I make sure that at all times every node is under 50% of its disk > space? Are there any normal day-to-day operations that would cause the any > one node to double in size that I should be aware of? If on or more nodes to > surpass the 50% mark, what should I plan to do? > > Thanks for any advice >
