2011/6/15 Yehuda Sadeh Weinraub <yehudasa@xxxxxxxxx>: > On Mon, Jun 13, 2011 at 7:35 PM, Simon Tian <aixt2006@xxxxxxxxx> wrote: >> Hi Yehuda, >> >>  ÂSo I list a table which describe the VM status and time needed >> during rbd snapshot operation: >> >> operation Â|  VM status         Â|  Âtime needed >> ----------------------------------------------------------------------------------------------------------------------- >> create   Â|  could be running     Â|  Âinstant >> delete   Â|  could be running     Â|  Âinstant >> rollback  Â|  need to be shutdown  |  Âneeds to go through all the objects >> list      |  could be running     Â|  Âinstant >> set      |  need to be shutdown  Â|  Âinstant >> >> Could you check this table, hope to get your correction or supplement. >> Thx very much! > > Basically ok, just note: > Â- you can only rollback externally (through the rbd tool, or via > librbd), so you need to unmount the relevant device > Â- setting of a snapshot can be done by setting the vm state, this can > be achieved when it's running Hmm, is vm need to be shutdown too when setting a snapshot, because of the IO state ( like file description. etc ) in the vm memory. For the snapshot rollback, a LAZYLOAD feature should be attractive: rollback is instant then vm could be boot soon with out waiting for going through the object, which may be a very long time. The objects needed at present were gone through at present, the rbd client go through other objects during the vm running. The disadvantage is that rbd client may need to query if LAZYLOAD is finished when creating a new snapshot? snapshot Thx Simon -- 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