OPTION(journal_zero_on_create, OPT_BOOL, false)
OPTION(journal_ignore_corruption, OPT_BOOL, false) // assume journal is not corrupt
+OPTION(rados_mon_op_timeout, OPT_DOUBLE, 0) // how many seconds to wait for a response from the monitor before returning an error from a rados operation. 0 means on limit.
+OPTION(rados_osd_op_timeout, OPT_DOUBLE, 0) // how many seconds to wait for a response from osds before returning an error from a rados operation. 0 means no limit.
+
OPTION(rbd_cache, OPT_BOOL, false) // whether to enable caching (writeback unless rbd_cache_max_dirty is 0)
OPTION(rbd_cache_writethrough_until_flush, OPT_BOOL, false) // whether to make writeback caching writethrough until flush is called, to be sure the user of librbd will send flushs so that writeback is safe
OPTION(rbd_cache_size, OPT_LONGLONG, 32<<20) // cache size in bytes