Hello I have two questions about OSD. 1) From the current READ ops, whether the OSD can provide the readahead strategy? that is : the clients send MOSDOp msg to read some objects of a file, the msg includes many read ops(we can define the first Op as to read the object we wan at this time, and other Ops is going to do readahead work), these Ops ask OSD to read some objects ahead and OSD don't reply to those Ops, they only need to reply the client when got the wanted object. So, at the next time to read the different objects of that file, it can got data from OSDs' cache,that will promote read performance. All the readahead work was done internal OSD cluster. 2) ceph use osd journal to keep perfect stability, but that decrease the write performance as we see, can we record just metadata of the WRITE op in journal write item, but not the whole data buffer,in that way we can reponse client quickly. If the OSD crashed, we can replay the journal, but at this time we need to request data from CLIENT, which increase the complexity. -- 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
