> On Dec 22, 2017, at 11:47 AM, Christer Holmberg > <[email protected]> wrote: > > Hi Thomas, > > ... > >>> Q1: >>> >>> The Abstract says: >>> >>> "The flexible file layout type is defined in this >>> document as an extension to pNFS which allows the use of storage >>> devices in a fashion such that they require only a quite limited >>> degree of interaction with the metadata server, using already >>> existing protocols." >>> >>> …and the Introduction says: >>> >>> "There are different layout types for different storage >>> systems and methods of arranging data on storage devices. This >>> document defines the flexible file layout type used with file-based >>> data servers that are accessed using the Network File System (NFS) >>> protocols: NFSv3 [RFC1813], NFSv4.0 [RFC7530], NFSv4.1 [RFC5661], and >>> NFSv4.2 [RFC7862].” >>> >>> But, there is no text about the existing file layout type, and how >>> this file layout types will improve things. >> >> It does not have to improve things, it is just a different layout type. > > But, shouldn't there be any description about the difference between the > existing file layout type? Is there some specific scenario in mind? Is there > some characteristic(s) specific to the flexible file layout type? > > I assume there was *SOME* reason for defining the flexible file layout type - > other than just defining a new layout type for the sake of it :)
The old type did not allow you to use NFSv3 to access the storage devices. Which is covered here: This document defines the flexible file layout type used with file-based data servers that are accessed using the Network File System (NFS) protocols: NFSv3 [RFC1813], NFSv4.0 [RFC7530], NFSv4.1 [RFC5661], and NFSv4.2 [RFC7862]. DISCLAIMER: I am too close to this document and after RFC 7530 and RFC 7862, I tend to be terse. In general, a new layout type is created to access the storage devices via a different protocol than provided by existing layout types. See RFC 8154 and draft-hellwig-nfsv4-rdma-layout-00. I’ll add some text to make apparent the desire is to access non-NFSv4 storage devices. > >>> The Abstract mentions impacts on the interactions with the metadata server, >>> but there is no text about that >>> in the Introduction. >> >> There is, but perhaps the relationship needs to be explained. >> >> The entire second paragraph is about the interactions with the metadata >> server. > > If that is specific to the flexible file layout type, I think it should be > explicitly stated. > >>> I think a few sentences in the Introduction, describing the high-level >>> advantages and changes that the flexible file layout type brings, >>> would be good. >>> >>> Also, the Abstract mentions client mirroring, but there is nothing >>> about that in the Introduction. >>> >> >> Both of these were on purpose - I wanted to introduce the terms in Section >> 1.1 before using them. > > That is fine. > >> I’ll add the high-level summary, including client side mirroring. > > Thanks! > > >>> Q2: >>> >>> Is section 2 specific to the flexible file layout type, or is it about >>> pNFS in general? I think it would good to have a sentence describing >>> the scope of the section. >> >> It starts out general for all pNFS and covered more specifically in >> [pNFSLayouts]. >> >> And having said that, I disagree with it immediately. > > Disagree with what? My suggestion to have a sentence describing the scope? No, hah! My statement of "It starts out general for all pNFS and covered more specifically in [pNFSLayouts].” > >> I can point the reader to [pNFSLayouts] and paint the scope as to how >> FlexFiles will address this issue. > > Thanks! > > Regards, > > Christer > _______________________________________________ Gen-art mailing list [email protected] https://www.ietf.org/mailman/listinfo/gen-art
