Hello, In http://ceph.com/docs/next/rbd/rbd-config-ref/ it is said that: "The kernel driver for Ceph block devices can use the Linux page cache to improve performance." Is there anywhere that provides more details about this? As in, "can" implies that it might need to be enabled somewhere, somehow. Are there any parameters that influence it like the ones on that page mentioned above (which I assume are only for the user space aka librbd)? Also on that page we read: "Since the cache is local to the client, there’s no coherency if there are others accesing the image. Running GFS or OCFS on top of RBD will not work with caching enabled." This leads me to believe that enabling the RBD cache (or having it enabled somehow in the kernel module) would be a big no-no when it comes to KVM/qemu live migrations, seeing how the native KVM disk caching also needs to be disabled for it to work. Am I correct in that assumption? Regards, Christian -- Christian Balzer Network/Systems Engineer chibi@xxxxxxx Global OnLine Japan/Fusion Communications http://www.gol.com/ _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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