On Sun, Jun 12, 2011 at 7:02 AM, Simon Tian <aixt2006@xxxxxxxxx> wrote: > > hi guys, > > I have some questions about librbd snapshot: > > int snap_create(const char *snapname); > int snap_remove(const char *snapname); > int snap_rollback(const char *snap_name); > int snap_set(const char *snap_name); > > int copy(IoCtx& src_io_ctx, const char *srcname, IoCtx& dest_io_ctx, > const char *destname); > > If I create a snapshot S1, and then write 10GB data, and then I want > to create a snapshot S2. About how long time will the "snap_create" > take? May take just several seconds? Yes. It updates the header, and sends notifications (through the osd) to the other clients. > And how long will it task when remove S2? Same as creating it. > How long when rollback to S1? Rollback is (currently) is in the order of the number of object of that image. It needs to go through all the objects and execute an explicit request of each. For very large images it can be quite long. > How long when set to S1? Setting the snapshot context is instantaneous, client-side only operation. > > When I open snapshot S2 as an io_ctx, and copy it with the copy > interface, how long time will it spent? > Should be similar to rollback. Yehuda -- 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
