On Wednesday, April 18, 2012 at 5:50 AM, Martin Mailand wrote: > Hi, > > I changed the values and the performance is still very good and the > memory footprint is much smaller. > > OPTION(client_oc_size, OPT_INT, 1024*1024* 50) // MB * n > OPTION(client_oc_max_dirty, OPT_INT, 1024*1024* 25) // MB * n (dirty > OR tx.. bigish) > OPTION(client_oc_target_dirty, OPT_INT, 1024*1024* 8) // target dirty > (keep this smallish) > // note: the max amount of "in flight" dirty data is roughly (max - target) > > But I am not quite sure about the meaning of the values. > client_oc_size Max size of the cache? > client_oc_max_dirty max dirty value before the writeback starts? > client_oc_target_dirty ??? > Right now the cache writeout algorithms are based on amount of dirty data, rather than something like how long the data has been dirty. client_oc_size is the max (and therefore typical) size of the cache. client_oc_max_dirty is the largest amount of dirty data in the cache — if this much is dirty and you try to dirty more, the dirtier (a write of some kind) will block until some of the other dirty data has been committed. client_oc_target_dirty is the amount of dirty data that will trigger the cache to start flushing data out. -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
