Hi guys, Apologize if this question has been asked before. I'd like to know if it is safe to enable rbd cache with qemu (cache mode set as writeback) in production? Currently, there are 4 types of guest os supported in our production: REHL5, RHEL6, Win2k3, Win2k8. Our host is RHEL6.2 on which qemu supports 'barrier-passing'. Thus we have confident that RHEL6 guests(with barrier enabled by default) could work well with rbd cache enabled. But as for REHL5, Win2k3 and Win2k8, I am not sure if it is 100% safe on scenarios such as guest crash, host crash or power loss. Could anybody give some suggestion? Really appreciate your help. Yufang -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.ceph.com/pipermail/ceph-users-ceph.com/attachments/20140822/f93f22a4/attachment.htm>