pNFS Release Notes

Release Notes for OpenSolaris pNFS - March 16, 2009

Changes from the Last Release

Our project gate has been synced with build 110 of OS/Net Nevada (ONNV).
Our project gate is compliant with Draft 29 of the NFSv4.1 specification. Please make sure use the same software level for client and server installations.

General Information

These are the release notes for the March 16, 2009 release of the source code and binaries for the OpenSolaris project "NFS version 4.1 pNFS". The purpose of this document is to give you information about this distribution, its capabilities, known problems, and installation instructions. A separate document contains directions on how to configure pNFS clients and servers.

We value your feedback and thank you for trying pNFS!

If you have questions or comments about this document, the software being released, the logistics of the pNFS project, please email them to nfsv41-discuss@opensolaris.org.

If you run into problems or issues not mentioned in the known issue list below, please report them via the email address mentioned above. Provide the release date as well as information about the problem. Information that will help in determining the root cause of a problem is documented in the FAQ.

Although we will not be providing patches or fixes to this distribution, we will enter the issues into our tracking tool and evaluate each issue for inclusion in future releases of this project. If you are interested in contributing to the project, please contact us.

This release is based off of OS/Net Nevada (ONNV) Build 110.

Functionality

This release implements the basic elements needed for doing files-based pNFS as defined by draft 29 of the NFSv4.1 specification. This specification is owned by the IETF and the latest draft may be viewed on the IETF website. Various versions of the draft can also be viewed on the NFSv4.1 Editor's website.

At a high level, this distribution supports separation of data and metadata, parallel I/O from the pNFS clients to pNFS data servers, and Sessions, a mandatory-to-implement feature of the NFSv4.1 specification and a prerequisite for pNFS.

Since we are early in the development cycle, some features have yet to be implemented. We recommend this release for experimental or casual use (i.e., install it just to "play around" with pNFS).

This release is not to be used in production environments. There are known issues which will cause system crashes.

Known Issues

Upon startup of the data server (dservadm enable) an error message like the one below will be emitted. This message is harmless.
dserv[some number]: bad cmd: 3

Recovery from data server or metadata server error is not fully implemented. If a data server or metadata server fails (reboots) the machines in your setup (including client and servers) may have to be rebooted.

If a file is created with a given number of data servers and the MDS is restarted with a different number of data servers then the data to previously existing files may be inaccessible or incorrect.

The NFSv4.1/pNFS client will auto-negotiate the correct NFSv4 Minor Version for you. If you run your NFSv4.1 client against a NFSv4.0 server running Solaris 10 or a Solaris Nevada build older than ONNV build 70 you will see messages like the one below. These messages are harmless and are just a side effect of the client negotiating the correct Minor Version.
NFS4 compound failed for <server_name>: RPC: Server can't decode arguments
NOTICE: NFS4 mount (EXCHANGE_ID failed): Create Clientid failure

There is currently no way to remove data objects from the data server. Removal of files from the metadata server will work as normal, but this won't deallocate the space on the data server. Therefore, over time your data server will fill up. Once it fills up the data server will start reporting I/O errors. To recover, destroy your zpool and recreate it (yes, all data will be gone).

Accessing pNFS files directly at the MDS is not supported. The file's attributes, including size, will be correct, but the file's data will read as all zeros. Modifying the file's data locally at the MDS will succeed; however, the client will not see this data.

The use of Kerberos with NFSv4.1 mounts is currently untested and discouraged.

RDMA is not currently supported for NFSv4.1

Running the MDS or DS in a non-global zone is not supported.

The mdsadm and dservadm commands are very preliminary and will be changed in the future. No man pages are available, but the "how to" document contains descriptions of them.

Instructions for Installing

See the "how to".