On Thu, Jul 12, 2012 at 12:04:24PM +0300, Samuli Heinonen wrote: > >So am I kidding myself that approaching 45-50MB/s with a > >FUSE based Gluster mount and using cache=writethrough is actually > >a safe thing to do really? ... > When using writethrough the data is written to cache but not marked > finished before it has hit the disk. Data in cache can be then used > to speed up read operations. So I would consider it pretty safe, but > perhaps someone else can explain it better? I don't believe he is getting that speed with cache=writethrough. I think he means cache=writeback. http://www.linux-kvm.org/page/Tuning_KVM "QEMU also supports a wide variety of caching modes. Writeback is useful for testing but does not offer storage guarantees. Writethrough (the default) is safer, and relies on the host cache."
