On 15 Apr 2016, at 04:09, Eric Blake <ebl...@redhat.com> wrote: > +## Block sizes > + > +During transmission phase, several operations are constrained by the > +export size sent by the final `NBD_OPT_EXPORT_NAME` or `NBD_OPT_GO`, > +as well as by three block sizes defined here (minimum, preferred, and > +maximum). During the handshake phase, a client MAY announce its > +intention to honor server block sizes via the experimental > +`BLOCK_SIZE` extension; see below.
"If a client can honor server block sizes (as set out in the experimental `BLOCK_SIZE` extension) it SHOULD announce this during the handshake phase" > A client that is worried about > +block size constraints SHOULD use `NBD_OPT_GO` rather than > +`NBD_OPT_EXPORT_NAME`. "Such a client SHOULD use"... > A server SHOULD advertise the block size > +contraints during handshake phase via the experimental `INFO` > +extension; see below. A server and client MAY agree on block sizes > +via out of band means. > + > +If block sizes have not been advertised or agreed on externally, then > +a client SHOULD assume a default minimum block size of 1, a preferred > +block size of 4,096, and no inherent maximum block size. A server > +that wants to enforce block sizes other than the defaults specified > +here MUST support the experimental `INFO` extension, and MAY refuse to > +go into transmission phase for a client that uses s/for/with/ > +The maximum block size represents the maximum length that the server > +is willing to handle in one request. If advertised, it MUST be either > +an integer multiple of the minimum block size or the value > +4,294,967,295 (that is, (uint32_t)-1) for no inherent limit, MUST be > +at least as large as the preferred block size, and SHOULD be at least > +3,355,442 (32M), That looks more like 3MB to me? otherwise LGTM -- Alex Bligh ------------------------------------------------------------------------------ Find and fix application performance issues faster with Applications Manager Applications Manager provides deep performance insights into multiple tiers of your business applications. It resolves application problems quickly and reduces your MTTR. Get your free trial! https://ad.doubleclick.net/ddm/clk/302982198;130105516;z _______________________________________________ Nbd-general mailing list Nbd-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nbd-general
