At Mon, 8 Aug 2011 16:44:58 +0100, Brian Candler wrote: > > I am considering using a Sheepdog-based KVM cluster to run a Postgres > database, where data consistency is important. > > Are there any problems or issues I should consider in this application? Does > Sheepdog support write barriers? Should I use ext4 with journal > checksumming? Yes, both would work with Sheepdog. > > I notice the design doc says "The write request is successful only when all > replicas can be successfully updated", so I guess fsync shouldn't return > until all data has been written. Yes, exactly. > But I'd be grateful for any real-world experiences with databases on > KVM+Sheepdog. I think the performance could be a problem. The latency of a Sheepdog is higher than other local disk formats because of data replication and network latency, so Sheepdog would show a poorer performance with something like databases. Thanks, Kazutaka |