Hi, I notice a bug report on Bugzilla [1]. Quoting from it: > Justification: The server-side copy of small files takes more time than the R/W copy in NFS 4.2. > When I have two NFS 4.2 files systems from the same NFS server mounted in my linux client & I issue a copy operation between one file system to the other file system, the linux client issues server side copy of NFS 4.2 with COPY_NOTIFY packet. > If these two file systems are part of two different server, the same linux client issues server side copy of NFS 4.2 with COPY_NOTIFY packet only if the file size is more than 128 KB. > For less <= 128 KB files the client uses READ and WRITE operations in case of inter server copy. > > As the protocol does not specify any way for the server to drive the client for switching to the legacy file copy method, the same mechanism for the inter-server server-side copy could be applied to the intra-server copy as well. > > The request has two parts. > 1. Introduce one config parameter in "/etc/nfs.conf" where a user can provide the minimum file size required for COPY_NOTIFY operation. Default it to 128 KB. If the file size is less, the client should use READ and WRITE operations instead of COPY_NOTIFY for both inter & intra server copy in NFS 4.2 mount. > > 2. Modify how intra server copy is handled now. It should follow similar approach as followed by inter server copy. It should utilize the config variable from point 1 to decide between "READ and WRITE operation" and "COPY_NOTIFY". > > Reproducible: Always > > Steps to Reproduce: > 1.Configure two Linux NFS 4.2 server & take one Fedora 38 client. > 2.Configure 2 file system in one server and one file system in another server. > 3.Initiate file copy between file systems in the same server. > 4.Also initiate file copy between file systems in the two different server. > 5.Try step 3-4 with file size of 1 byte, 128 KB & 129 KB files. > 6.Take packet capture and see the content. > > Actual Results: > For inter server copy, > It uses COPY_NOTIFY operation for file size more than 128 KB. for <= 128 KB it use READ and WRITE operations. > For intra server copy, > It uses COPY_NOTIFY operation for all file sizes > > Expected Results: > 1. One new parameter is introduced in nfs.conf to configure minimum file size for COPY_NOTIFY operation with a default value 128 KB. > 2. For file sizes more than the configured value or more than 128KB if not configured, the client should issue COPY_NOTIFY operation for intra & inter server copy. > 3. For other case, it should use READ and WRITE operations instead of COPY_NOTIFY for both inter & intra server copy in NFS 4.2 mount > > The test was done with > Fedora Linux 38 (Workstation Edition) with > Kernel 6.4.4-200.fc38.x86_64 > > I have also attached packet capture of 1 byte, 128 KB & > 128 KB file copy operation for your reference. See Bugzilla for the full thread and attached tcpdump output. Note that I have to forward the Bugzilla report by this email because the reporter chose generic `Kernel` component when filing it, thus missing linux-nfs list. The reporter's address is also in To: field so that you can reach him without having to go to Bugzilla. Thanks. [1]: https://bugzilla.kernel.org/show_bug.cgi?id=217749 -- An old man doll... just what I always wanted! - Clara
