Sorry for missing subject. On 08/21/2014 03:09 PM, Pawe? Sadowski wrote: > Hi, > > I'm trying to start Qemu on top of RBD. In documentation[1] there is a > big warning: > > Important > > If you set rbd_cache=true, you must set cache=writeback or risk data > loss. Without cache=writeback, QEMU will not send flush requests to > librbd. If QEMU exits uncleanly in this configuration, filesystems > on top of rbd can be corrupted. > > But in last part of that page there is written that Qemu command line > override ceph.conf settings and setting *cache=writethrough* will force > *rbd_cache**=**true* and *rbd_cache_max_dirty=0*. In that configuration > rbd will write directly to Ceph and there is no risk of data loss > (except for things cached in VM OS). Am I right or am I missing something? > > 1: http://ceph.com/docs/master/rbd/qemu-rbd/ > > Thanks, > PS
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