Thanks, haomai. I worry about if all guest file systems are so serious like you said. For rhel5, barrier is not enabled by default. For windows, I even do not know how to enable it? Do you think there is no chance that guest file system being corrupted on host/guest crash? ???? iPad > ? 2014?8?22??22:52?Haomai Wang <haomaiwang at gmail.com> ??? > > Seriously it's safe to use rbd cache for vm. Rbd cache behavior like > disk cache which is flushed via "fsync" or "fdatasync" calls. > A serious application will take care of it. > > On Fri, Aug 22, 2014 at 7:05 PM, Yufang Zhang <yufang521247 at gmail.com> wrote: >> 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 >> >> _______________________________________________ >> ceph-users mailing list >> ceph-users at lists.ceph.com >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > > -- > Best Regards, > > Wheat
 |