NFSv4 Working Group J. Lentini Internet-Draft C. Everhart Intended status: Standards Track NetApp Expires: July 25, 2010 D. Ellard BBN Technologies R. Tewari M. Naik IBM Almaden January 21, 2010 Administration Protocol for Federated Filesystems draft-ietf-nfsv4-federated-fs-admin-04 Abstract This document describes the administration protocol for a federated file system that enables file access and namespace traversal across collections of independently administered fileservers. The protocol specifies a set of interfaces by which fileservers with different administrators can form a fileserver federation that provides a namespace composed of the filesystems physically hosted on and exported by the constituent fileservers. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. Lentini, et al. Expires July 25, 2010 [Page 1] Internet-Draft Admin Protocol for Federated Filesystems January 2010 The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on July 25, 2010. Copyright Notice Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the BSD License. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English. Lentini, et al. Expires July 25, 2010 [Page 2] Internet-Draft Admin Protocol for Federated Filesystems January 2010 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Error Values . . . . . . . . . . . . . . . . . . . . . . . . . 7 4. Data Types . . . . . . . . . . . . . . . . . . . . . . . . . . 9 5. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 10 5.1. FEDFS_CREATE_JUNCTION . . . . . . . . . . . . . . . . . . 11 5.2. FEDFS_DELETE_JUNCTION . . . . . . . . . . . . . . . . . . 13 5.3. FEDFS_LOOKUP_FSN . . . . . . . . . . . . . . . . . . . . . 14 5.4. FEDFS_SET_NSDB_PARAMS . . . . . . . . . . . . . . . . . . 16 5.5. FEDFS_GET_NSDB_PARAMS . . . . . . . . . . . . . . . . . . 16 5.6. FEDFS_GET_LIMITED_NSDB_PARAMS . . . . . . . . . . . . . . 17 6. Security Considerations . . . . . . . . . . . . . . . . . . . 18 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 8. Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 21 9.1. Normative References . . . . . . . . . . . . . . . . . . . 21 9.2. Informative References . . . . . . . . . . . . . . . . . . 21 Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . . 22 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 22 Lentini, et al. Expires July 25, 2010 [Page 3] Internet-Draft Admin Protocol for Federated Filesystems January 2010 1. Introduction A federated filesystem enables file access and namespace traversal in a uniform, secure and consistent manner across multiple independent fileservers within an enterprise (and possibly across multiple enterprises) with reasonably good performance. Traditionally, building a namespace that spans multiple fileservers has been difficult for two reasons. First, the fileservers that export pieces of the namespace are often not in the same administrative domain. Second, there is no standard mechanism for the fileservers to cooperatively present the namespace. Fileservers may provide proprietary management tools and in some cases an administrator may be able to use the proprietary tools to build a shared namespace out of the exported filesystems. Relying on vendor- proprietary tools does not work in larger enterprises or when collaborating across enterprises because it is likely that the system will contain fileservers running different software, each with their own protocols, with no common protocol to manage the namespace or exchange namespace information. The requirements for federated namespaces are described in [FEDFS-REQTS]. The filesystem federation protocol described in [FEDFS-NSDB] allows fileservers from different vendors and/or with different administrators to cooperatively build a namespace. This document describes the protocol used by administrators to configure the fileservers and construct the namespace. 2. Protocol The RPC protocol used by the administration operations is ONC RPC [RFC5531]. The data structures used for the parameters and return values of these procedures are expressed in this document in XDR [RFC4506]. The XDR definitions below are formatted to allow the reader to easily extract them from the document. The reader can use the following shell script to extract the definitions: #!/bin/sh grep '^ *///' | sed 's?^ */// ??' | sed 's?^ *///$??' Lentini, et al. Expires July 25, 2010 [Page 4] Internet-Draft Admin Protocol for Federated Filesystems January 2010 If the above script is stored in a file called "extract.sh", and this document is in a file called "spec.txt", then the reader can do: sh extract.sh < spec.txt > admin1.xdr The effect of the script is to remove leading white space from each line, plus a sentinel sequence of "///". The protocol definition in XDR notation is shown below. We begin by defining basic constants and structures used by the protocol. We then present the procedures defined by the protocol. /// enum FedFsStatus { /// FEDFS_OK = 0, /// FEDFS_ERR_ACCESS = 1, /// FEDFS_ERR_BADCHAR = 2, /// FEDFS_ERR_BADXDR = 3, /// FEDFS_ERR_EXIST = 4, /// FEDFS_ERR_INVAL = 5, /// FEDFS_ERR_IO = 6, /// FEDFS_ERR_NOSPC = 7, /// FEDFS_ERR_NOTDIR = 8, /// FEDFS_ERR_NOTEMPTY = 9, /// FEDFS_ERR_NOTJUNCT = 10, /// FEDFS_ERR_NOTLOCAL = 11, /// FEDFS_ERR_PERM = 12, /// FEDFS_ERR_ROFS = 13, /// FEDFS_ERR_SVRFAULT = 14, /// FEDFS_ERR_NSDB_ROUTE = 15, /// FEDFS_ERR_NSDB_DOWN = 16, /// FEDFS_ERR_NSDB_CONN = 17, /// FEDFS_ERR_NSDB_AUTH = 18, /// FEDFS_ERR_NSDB_LDAP = 19, /// FEDFS_ERR_NSDB_NOFSN = 20, /// FEDFS_ERR_NSDB_NOFSL = 21, /// FEDFS_ERR_NSDB_RESPONSE = 22, /// FEDFS_ERR_NSDB_FAULT = 23, Lentini, et al. Expires July 25, 2010 [Page 5] Internet-Draft Admin Protocol for Federated Filesystems January 2010 /// FEDFS_ERR_NSDB_PARAMS = 24 /// }; /// /// typedef opaque FedFsUuid<16>; /// /// typedef opaque FedFsNsdbName<>; /// /// typedef opaque FedFsPathComponent<>; /// typedef FedFsPathComponent FedFsPathName<>; /// /// typedef opaque FedFsNsdbContainerEntry<>; /// /// struct FedFsFsn { /// FedFsUuid fsnUuid; /// FedFsNsdbName nsdbName; /// FedFsNsdbContainerEntry nce; /// }; /// /// struct FedFsCreateJunctionArgs { /// FedFsPathName path; /// FedFsFsn fsn; /// }; /// /// enum FedFsResolveType { /// FEDFS_RESOLVE_NONE = 0, /// FEDFS_RESOLVE_CACHE = 1, /// FEDFS_RESOLVE_NSDB = 2 /// }; /// /// struct FedFsLookupFsnArgs { /// FedFsPathName path; /// FedFsResolveType resolve; /// }; /// /// union FedFsResolveRes switch (FedFsResolveType resolve) { /// case FEDFS_RESOLVE_NONE: /// void; /// default: /* CACHE or NSDB */ /// FedFsUuid fslUuid<>; /// }; /// /// struct FedFsLookupFsnResOk { /// FedFsFsn fsn; /// FedFsResolveRes resolveResult; /// }; /// /// union FedFsLookupFsnRes switch (FedFsStatus status) { /// case FEDFS_OK: Lentini, et al. Expires July 25, 2010 [Page 6] Internet-Draft Admin Protocol for Federated Filesystems January 2010 /// FedFsLookupFsnResOk resok; /// case FEDFS_ERR_NSDB_LDAP: /// unsigned int ldapResultCode<1>; /// default: /// void; /// }; /// /// enum FedFsConnectionSec { /// FEDFS_SEC_NONE = 0, /// FEDFS_SEC_TLS = 1 /* StartTLS mechanism; RFC4513, Section 3 */ /// /* other mechanisms TBD */ /// }; /// /// struct FedFsNsdbParams { /// FedFsConnectionSec secType; /// /* type specific data follows */ /// opaque secData<>; /// }; /// /// struct FedFsSetNsdbParamsArgs { /// FedFsNsdbName nsdbName; /// FedFsNsdbParams params; /// }; /// /// union FedFsGetNsdbParamsRes switch (FedFsStatus status) { /// case FEDFS_OK: /// FedFsNsdbParams params; /// default: /// void; /// }; /// /// union FedFsGetLimitedNsdbParamsRes switch (FedFsStatus status) { /// case FEDFS_OK: /// FedFsConnectionSec secType; /// default: /// void; /// }; /// /// program FEDFS_PROG { /// version FEDFS_VERSION { /// void FEDFS_NULL(void) = 0; /// FedFsStatus FEDFS_CREATE_JUNCTION( /// FedFsCreateJunctionArgs) = 1; /// FedFsStatus FEDFS_DELETE_JUNCTION( /// FedFsPathName) = 2; /// FedFsLookupFsnRes FEDFS_LOOKUP_FSN( /// FedFsLookupFsnArgs) = 3; /// FedFsStatus FEDFS_SET_NSDB_PARAMS( Lentini, et al. Expires July 25, 2010 [Page 7] Internet-Draft Admin Protocol for Federated Filesystems January 2010 /// FedFsSetNsdbParamsArgs) = 4; /// FedFsGetNsdbParamsRes FEDFS_GET_NSDB_PARAMS( /// FedFsNsdbName) = 5; /// FedFsGetLimitedNsdbParamsRes FEDFS_GET_LIMITED_NSDB_PARAMS( /// FedFsNsdbName) = 6; /// } = 1; /// } = 100418; 3. Error Values The results of successful operations will consist of a status of FEDFS_OK. The results of unsuccessful operations will begin with a status, other than FEDFS_OK, that indicates the reason why the operation failed. Many of the error status names and meanings (and the prose for their descriptions) are taken from the specification for NFSv4 [RFC3530]. Note, however, that the literal values for the status codes are different. Note that the status of an unsuccessful operation will generally only indicate the first error encountered during the attempt to execute the operation. FEDFS_OK No errors were encountered. The operation was a success. FEDFS_ERR_ACCESS Permission denied. The caller does not have the correct permission to perform the requested operation. FEDFS_ERR_BADCHAR A UTF-8 string contains a character which is not supported by the server in the context in which it being used. FEDFS_ERR_BADXDR The server encountered an XDR decoding error while processing an operation. FEDFS_ERR_EXIST The junction specified already exists. FEDFS_ERR_INVAL Invalid argument for an operation. FEDFS_ERR_IO A hard error occurred while processing the requested operation. Lentini, et al. Expires July 25, 2010 [Page 8] Internet-Draft Admin Protocol for Federated Filesystems January 2010 FEDFS_ERR_NOSPC The requested operation would have caused the server's filesystem to exceed some limit (for example, if there is a fixed number of junctions per fileset or per server). FEDFS_ERR_NOTDIR The caller specified a non-directory in an operation that requires a directory. FEDFS_ERR_NOTEMPTY The caller specified a directory that is not empty as the operand of an operation that requires an empty directory. FEDFS_ERR_NOTJUNCT The caller specified a path that does not end in a junction as the operand for an operation that requires the last component of the path to be a junction. FEDFS_ERR_NOTLOCAL The caller specified a path that contains a junction in any position other than the last component. FEDFS_ERR_PERM The operation was not allowed because the caller is either not a privileged user or not the owner of an object that would be modified by the operation. FEDFS_ERR_ROFS A modifying operation was attempted on a read-only filesystem. FEDFS_ERR_SVRFAULT An unanticipated non-protocol error occurred on the server. FEDFS_ERR_NSDB_ROUTE The fileserver was unable to find a route to the NSDB. FEDFS_ERR_NSDB_DOWN The fileserver determined that the NSDB was down. FEDFS_ERR_NSDB_CONN The fileserver was unable to establish a connection with the NSDB. FEDFS_ERR_NSDB_AUTH The fileserver was unable to authenticate and establish a secure connection with the NSDB. FEDFS_ERR_NSDB_LDAP An LDAP error occurred on the connection between the fileserver and NSDB. FEDFS_ERR_NSDB_NOFSN The fileserver was unable to locate the given FSN in the appropriate NSDB. Lentini, et al. Expires July 25, 2010 [Page 9] Internet-Draft Admin Protocol for Federated Filesystems January 2010 FEDFS_ERR_NSDB_NOFSL The fileserver was unable to locate any FSLs for the given FSN in the appropriate NSDB. FEDFS_ERR_NSDB_NOFSL The fileserver received a malformed response from the NSDB. FEDFS_ERR_NSDB_FAULT An unanticipated error related to the NSDB occurred. FEDFS_ERR_NSDB_PARAMS The fileserver does not have any connection parameters on record for the specified NSDB. 4. Data Types The basic data types defined above MUST be formatted as follows: FedFsUuid: A universally unique identifier (UUID) as described in [RFC4122] as a version 1 UUID. The UUID should be formatted in network byte order. FedFsNsdbName: A variable length UTF-8 string that represents an NSDB's network location in DNS name notation. The DNS name MUST be represented using a fully qualified domain name followed by an optional ":port" suffix where "port" is the UTF-8 string representing the transport port number's decimal value. A system (i.e. fileserver or administrative host) SHOULD resolve the fully qualified domain name to a network address using the system's standard resolution mechanisms. If the optional port suffix is omitted, the standard LDAP port number, 389, SHOULD be assumed. FSNs are immutable and invariant. The attributes of an FSN, including the fedfsNsdbName, are expected to remain constant. Therefore, a fedfsNsdbName SHOULD NOT contain a network address, such as an IPv4 or IPv6 address, as this would indefinitely assign the network address. FedFsPathComponent: A case sensitive UTF-8 string containing a filesystem path component. FedFsPathName: A variable length array of FedFsPathComponent values representing a filesystem path. The path's first component is stored at the first position of the array, the second component is stored at the second position of the array, and so on. Lentini, et al. Expires July 25, 2010 [Page 10] Internet-Draft Admin Protocol for Federated Filesystems January 2010 FedFsNsdbContainerEntry: A case sensitive UTF-8 string containing the distinguished name of the NSDB Container Entry (NCE). A string of up to 128 characters MUST be supported. A string greater than 128 characters MAY be supported. FedFsNsdbParams: A set of parameters for connecting to an NSDB. Conceptually the fileserver contains a data structure that maps an NSDB name (DNS name and port value) to these LDAP connection parameters. The secType field indicates the security mechanism that MUST be used to protect all connections to the NSDB with the connection parameters. A value of FEDFS_SEC_NONE indicates that no security mechanism is necessary. In this case, the secData array will have 0 (zero) length. A value of FEDFS_SEC_TLS indicates that the StartTLS security mechanism [RFC4513] MUST be used to protect all connections to the NSDB. In this case, the secData array will contain an X.509v3 certificate in binary DER format [RFC5280]. The certificate SHOULD be used by the fileserver to authenticate the identity of the NSDB. In particular, this certificate SHOULD be used to validate the NSDB's TLS certificate list chain (see 7.4.2 of [RFC5246]). The certificate could be that of a certificate authority or a self-signed certificate. 5. Procedures Fileservers that participate as "internal" nodes in the federated namespace MUST provide these procedures: FEDFS_NULL The null RPC, which is included, by convention, in every ONC RPC protocol. FEDFS_CREATE_JUNCTION Create a new junction from some location on the server (defined as a pathname) to an FSN. FEDFS_DELETE_JUNCTION Delete an existing junction from some location on the server (defined as a pathname). FEDFS_LOOKUP_FSN Query the server to discover the current value of the junction (if any) at a given path in the server namespace. Lentini, et al. Expires July 25, 2010 [Page 11] Internet-Draft Admin Protocol for Federated Filesystems January 2010 FEDFS_SET_NSDB_PARAMS Set the connection parameters for the specified NSDB. FEDFS_GET_NSDB_PARAMS Get the connection parameters for the specified NSDB. FEDFS_GET_LIMITED_NSDB_PARAMS Get a limited subset of the connection parameters for the specified NSDB. The FEDFS_CREATE_JUNCTION, FEDFS_DELETE_JUNCTION, FEDFS_LOOKUP_FSN, FEDFS_SET_NSDB_PARAMS, FEDFS_GET_NSDB_PARAMS, and FEDFS_GET_LIMITED_NSDB_PARAMS procedures are described in more detail in the following sections. Fileservers that participate as "leaf" nodes in the namespace (i.e., fileservers that host filesets that are the target of junctions, but that do not contain any junctions) are not required to implement any of these operations. Note that operations that modify the state of a replicated fileset MUST result in the update of all of the replicas in a consistent manner. Ideally all of the replicas SHOULD be updated before any operation returns. If one or more of the replicas are unavailable, the operation MAY succeed, but the changes MUST be applied before the unavailable replicas are brought back online. We assume that replicas are updated via some protocol that permits state changes to be reflected consistently across the set of replicas in such a manner that the replicas will converge to a consistent state within a bounded number of successful message exchanges between the servers hosting the replicas. 5.1. FEDFS_CREATE_JUNCTION This operation creates a junction from a server-relative path to a (potentially) remote fileset named by the given FSN. The junction directory on the server is identified by a pathname in the form of an array of one or more UTF-8 path component strings. It is not required that this path be accessible in any other manner (e.g., to a client). This path does not appear in the federated namespace, except by coincidence; there is no requirement that the global namespace parallel the server namespace, nor is it required that this path be relative to the server pseudo-root. It does not need to be a path that is accessible via NFS (although the junction will be of limited utility if the directory specified by the path is not also accessible via NFS). If the fileset is read-only, then this operation SHOULD indicate this Lentini, et al. Expires July 25, 2010 [Page 12] Internet-Draft Admin Protocol for Federated Filesystems January 2010 with a status of FEDFS_ERR_ROFS. If the path contains an invalid UTF-8 character, then status FEDFS_ERR_BADCHAR must be returned. The path is REQUIRED to exist and be completely local to the server. It MUST NOT contain a junction. If the last component of the path is a junction (i.e., this operation is attempting to create a junction where one already exists), then this operation MUST return the error FEDFS_ERR_EXISTS (even if the requested junction is identical to the current junction). If any other component of the path is a junction, then this operation MUST fail with status FEDFS_ERR_NOTLOCAL. The path may contain a symbolic link (if supported by the local server), but the traversal of the path must remain within the server-local namespace. The last component of the path MUST be an empty directory. If any component of the path does not exist, or the final component is not a directory, then the operation fails with status FEDFS_ERR_INVAL. The server MAY enforce the local permissions on the path, including the final component. If the path cannot be traversed because of insufficient permissions, or the final component is an unexecutable or unwritable directory, then the operation MAY fail with status FEDFS_ERR_ACCESS. The operation SHOULD fail with status FEDFS_ERR_NSDB_PARAMS if the fileserver does not have any connection parameters on record for the specified NSDB. The association between the path and the FSN MUST be durable before the operation may return successfully. If the operation return codes indicates success, then the caller may assume that the junction was successfully created and is immediately accessible. If successful, subsequent references via NFSv4 [RFC3530] or NFSv4.1 [NFSv4.1] clients to the directory that has been replaced by the junction will result in a referral to a current location of the target fileset [FEDFS-NSDB]. Note that the effective permissions of the directory that is converted, by this operation, into a junction are the permissions of the root directory of the target fileset. The original permissions of the directory (and any other attributes it might have) are subsumed by the junction. Note that this operation does not create a fileset at the location targeted by the junction. If the target fileset does not exist, the Lentini, et al. Expires July 25, 2010 [Page 13] Internet-Draft Admin Protocol for Federated Filesystems January 2010 junction will still be created. An NFS client will discover the missing fileset when it traverses the junction. 5.2. FEDFS_DELETE_JUNCTION This operation removes a junction specified by a server-relative path. As with FEDFS_CREATE_JUNCTION, the junction on the server is identified by a pathname in the form of an array of one or more UTF-8 path component strings. It is not required that this path be accessible in any other manner (e.g., to a client). This path does not appear in the federated namespace, except by coincidence; there is no requirement that the global namespace reflect the server namespace, nor is it required that this path be relative to the server pseudo-root. It does not need to be a path that is accessible via NFS. If the fileset is read-only, then this operation SHOULD indicate this with a status of FEDFS_ERR_ROFS. If the path contains an invalid UTF-8 character, then status FEDFS_ERR_BADCHAR must be returned. The path used to delete a junction might not be the same path that was used to create the junction. If the namespace on the server has changed, then the junction may now appear at a different path than where it was created. If there is more than one valid path to the junction, any of them may be used. The path is REQUIRED to exist and be completely local to the server. It MUST NOT contain a junction, except as the final component, which MUST be a junction. If any other component of the path is a junction, then this operation MUST fail with status FEDFS_ERR_NOTLOCAL. If the last component of the path is not a junction then this operation MUST return status FEDFS_ERR_INVAL. The path may contain a symbolic link (if supported by the local server), but the traversal of the path must remain within the server-local namespace. The last component of the path MUST be a junction. If any component of the path does not exist, or the final component is not a junction, then the operation fails with status FEDFS_ERR_NOTJUNCT. The server MAY enforce the local permissions on the path, including the final component. If the path cannot be traversed because of insufficient permissions, or the parent directory of the junction unexecutable or unwritable directory, then the operation MAY fail Lentini, et al. Expires July 25, 2010 [Page 14] Internet-Draft Admin Protocol for Federated Filesystems January 2010 with status FEDFS_ERR_ACCESS. The removal of the association between the path and the FSN MUST be durable before the operation may return successfully. If the operation return codes indicates success, then the caller may assume that the junction was successfully destroyed. The effective permissions and other attributes of the directory that is restored by this operation SHOULD be identical to their value prior to the creation of the junction. After removal of the junction, the fileserver MAY check if any of its existing junctions reference the NSDB specified in the removed junction's FSN. If the NSDB is not referenced, the fileserver MAY delete the connection parameters of the unreferenced NSDB. 5.3. FEDFS_LOOKUP_FSN This operation queries a server to determine whether a given path ends in a junction, and if so, the FSN to which the junction refers and the filerserver's ability to resolve the junction. Ordinary NFSv4 operations do not provide any general mechanism to determine whether an object is a junction -- there is no encoding specified by the NFSv4 protocol that can represent this information. As with FEDFS_CREATE_JUNCTION, the pathname must be in the form of an array of one or more UTF-8 path component strings. It is not required that this path be accessible in any other manner (e.g., to a client). This path does not appear in the federated namespace, except by coincidence; there is no requirement that the global namespace reflect the server namespace, nor is it required that this path be relative to the server pseudo-root. It does not need to be a path that is accessible via NFS. If the path contains an invalid UTF-8 character, then status FEDFS_ERR_BADCHAR must be returned. The path used to lookup a junction might not be the same path that was used to create the junction. If the namespace on the server has changed, then a junction may now appear at a different path than where it was created. If there is more than one valid path to the junction, any of them may be used. The path is REQUIRED to exist and be completely local to the server. It MUST NOT contain a junction, except as the final component. If any other component of the path is a junction, then this operation MUST fail with status FEDFS_ERR_NOTLOCAL. If the last component of Lentini, et al. Expires July 25, 2010 [Page 15] Internet-Draft Admin Protocol for Federated Filesystems January 2010 the path is not a junction then this operation MUST return the status FEDFS_ERR_NOTJUNCT. The path may contain a symbolic link (if supported by the local server), but the traversal of the path must remain within the server-local namespace. The server MAY enforce the local permissions on the path, including the final component. If the path cannot be traversed because of insufficient permissions, or the parent directory of the junction is an unexecutable or unwritable directory, then the operation MAY fail with status FEDFS_ERR_ACCESS. If the junction exists, the resolve parameter allows for testing the fileserver's ability to resolve the junction. If the junction does not exist, the fileserver will ignore the resolve parameter. If the junction exists and the resolve parameter is set to FEDFS_RESOLVE_NONE, the fileserver MUST NOT attempt to resolve the FSN. This will allow the administrator to obtain the junction's FSN even if the resolution would fail. If the junction exists and the resolve parameter is set to FEDFS_RESOLVE_CACHE, the fileserver MUST attempt to resolve the FSN using its FSL cache, if one exists. The fileserver MUST NOT resolve the FSN by contacting the appropriate NSDB. If the fileserver does not have a cache or its cache does not have a mapping for the FSN in question, the result of the operation MUST be FEDFS_OK with the FedFsResolveRes's resolve value set to FEDFS_RESOLVE_NONE. If the junction exists and the resolve parameter is set to FEDFS_RESOLVE_NSDB, the fileserver MUST attempt to resolve the FSN by contacting the appropriate NSDB. The FSN MUST NOT be resolved using cached information. The resolution MAY fail with FEDFS_ERR_NSDB_ROUTE, FEDFS_ERR_NSDB_DOWN, FEDFS_ERR_NSDB_CONN, FEDFS_ERR_NSDB_AUTH, FEDFS_ERR_NSDB_LDAP, FEDFS_ERR_NSDB_NOFSN, FEDFS_ERR_NSDB_NOFSL, FEDFS_ERR_NSDB_RESPONSE, or FEDFS_ERR_NSDB_FAULT depending on the nature of the failure. In the case of a FEDFS_ERR_NSDB_LDAP failure, the fileserver MAY indicate the LDAP protocol error value that was encountered in the FedFsLookupFsnRes's ldapResultCode (see the resultCode values in Section 4.1.9 of [RFC4511]). If the fileserver has a cache of FSL records, the process of resolving an FSN using an NSDB SHOULD result in the cache being updated. New FSLs for the given FSN SHOULD be added to the cache and deleted FSLs SHOULD be removed from the cache. This behavior is desirable because it allows an administrator to proactively request that the fileserver refresh its FSL cache. For example, the administrator might like to refresh the fileserver's cache when Lentini, et al. Expires July 25, 2010 [Page 16] Internet-Draft Admin Protocol for Federated Filesystems January 2010 changes are made to an FSN's FSLs. If the junction is resolved, the fileserver will indicate the type of resolution that was performed using the FedFsResolveRes's resolve value and include a list of UUIDs for the FSN's FSLs in the FedFsResolveRes's fslUuid array. 5.4. FEDFS_SET_NSDB_PARAMS This operations allows the administrator to set the connection parameters for a given NSDB. If a record for the given NSDB does not exist, a new record is created with the specified connection parameters. If a record for the given NSDB does exist, the existing connection parameters are replaced with the specified connection parameters. An NSDB is specified using a FedFsNsdbName. Two FedFsNsdbNames are considered equal if both their DNS name and port values are the same. As described above, the standard LDAP port number, 389, SHOULD be assumed if no port number is explicitly specified. Therefore, the FedFsNsdbName "nsdb.example.com" is considered equal to "nsdb.example.com:389" but not equal to "nsdb.example.com:1066" or "nsdb.foo.example.com:389. The given NSDB need not be referenced by any junctions on the fileserver. This situation will occur when connection parameters for a new NSDB are installed. The format of the connection parameters is described above. On success, this operation returns FEDFS_OK. When the operation returns, the new connection parameters SHOULD be used for all subsequent LDAP connections to the given NSDB. Existing connections MAY be terminated and re-established using the new connection parameters. The connection parameters SHOULD be durable across fileserver reboots. On failure, an error value indicating the type of error is returned. The operation MAY return FEDFS_ERR_ACCESS if the operation's associated user does not have sufficient permissions to create/modify NSDB connection parameters. 5.5. FEDFS_GET_NSDB_PARAMS This operations allows the administrator to retrieve connection parameters, if they exist, for the given NSDB. Lentini, et al. Expires July 25, 2010 [Page 17] Internet-Draft Admin Protocol for Federated Filesystems January 2010 An NSDB is specified using a FedFsNsdbName. Two FedFsNsdbNames are considered equal if both their DNS name and port values are the same. As described above, the standard LDAP port number, 389, SHOULD be assumed if no port number is explicitly specified. Therefore, the FedFsNsdbName "nsdb.example.com" is considered equal to "nsdb.example.com:389" but not equal to "nsdb.example.com:1066" or "nsdb.foo.example.com:389. A set of connection parameters is considered a match if their associated NSDB is equal (as defined above) to the operation's NSDB argument. Therefore, there is at most one set of connection parameters that can match the query described by this operation. The format of the connection parameters is described above. On success, this operation returns FEDFS_OK and the connection parameters on record for the given NSDB. On failure, an error value indicating the type of error is returned. This operation MAY return FEDFS_ERR_NSDB_PARAMS to indicate that there are no connection parameters on record for the given NSDB. The operation MAY return FEDFS_ERR_ACCESS if the operation's associated user does not have sufficient permissions to view NSDB connection parameters. 5.6. FEDFS_GET_LIMITED_NSDB_PARAMS This operations allows the administrator to retrieve a limited subset of information on the connection parameters, if they exist, for the given NSDB. An NSDB is specified using a FedFsNsdbName. Two FedFsNsdbNames are considered equal if both their DNS name and port values are the same. As described above, the standard LDAP port number, 389, SHOULD be assumed if no port number is explicitly specified. Therefore, the FedFsNsdbName "nsdb.example.com" is considered equal to "nsdb.example.com:389" but not equal to "nsdb.example.com:1066" or "nsdb.foo.example.com:389. A set of connection parameters is considered a match if their associated NSDB is equal (as defined above) to the operation's NSDB argument. Therefore, there is at most one set of connection parameters that can match the query described by this operation. This operation returns a limited subset of the connection parameters. Only the FedFsConnectionSec mechanism that is used to protect communication between the fileserver and NSDB is returned. Lentini, et al. Expires July 25, 2010 [Page 18] Internet-Draft Admin Protocol for Federated Filesystems January 2010 Viewing the limited subset of NSDB connection parameters returned by FEDFS_GET_LIMITED_NSDB_PARAMS MAY be a less privileged operation than viewing the entire set of NSDB connection parameters returned by FEDFS_GET_NSDB_PARAMS. For example, the full contents of an NSDB's connection parameters could contain sensitive information for some security mechanisms. FEDFS_GET_LIMITED_NSDB_PARAMS allows the fileserver to communicate a subset of the connection parameters (the security mechanism) to users with sufficient permissions without revealing more sensitive information. On success, this operation returns FEDFS_OK and the FedFsConnectionSec value on record for the given NSDB. On failure, an error value indicating the type of error is returned. This operation MAY return FEDFS_ERR_NSDB_PARAMS to indicate that there are no connection parameters on record for the given NSDB. The operation MAY return FEDFS_ERR_ACCESS if the operation's associated user does not have sufficient permissions to view the subset of NSDB connection parameters returned by this procedure. 6. Security Considerations The ONC RPC protocol supports authentication, integrity and privacy via the RPCSEC_GSS framework [RFC2203]. Fileservers which support the FedFS administration protocol described above MUST support RPCSEC_GSS. 7. IANA Considerations A range of ONC RPC program numbers were assigned for use by FedFS using the procedure described in Section 7.3 "Program Number Assignment" of [RFC5531]. The FedFS range is: IETF NFSv4 Working Group - FedFS 100418 - 100421 This document describes version 1 of the ONC RPC program 100418. 8. Glossary Administrator: user with the necessary authority to initiate administrative tasks on one or more servers. Lentini, et al. Expires July 25, 2010 [Page 19] Internet-Draft Admin Protocol for Federated Filesystems January 2010 Admin Entity: A server or agent that administers a collection of fileservers and persistently stores the namespace information. Client: Any client that accesses the fileserver data using a supported filesystem access protocol. Federation: A set of server collections and singleton servers that use a common set of interfaces and protocols in order to provide to their clients a federated namespace accessible through a filesystem access protocol. Fileserver: A server exporting a filesystem via a network filesystem access protocol. Fileset: The abstraction of a set of files and the directory tree that contains them. A fileset is the fundamental unit of data management in the federation. Note that all files within a fileset are descendants of one directory, and that filesets do not span filesystems. Filesystem: A self-contained unit of export for a fileserver, and the mechanism used to implement filesets. The fileset does not need to be rooted at the root of the filesystem, nor at the export point for the filesystem. A single filesystem MAY implement more than one fileset, if the client protocol and the fileserver permit this. Filesystem Access Protocol: A network filesystem access protocol such as NFSv2 [RFC1094], NFSv3 [RFC1813], NFSv4 [RFC3530], or CIFS (Common Internet File System) [MS-SMB] [MS-SMB2] [MS-CIFS]. FSL (Fileset Location): The location of the implementation of a fileset at a particular moment in time. An FSL MUST be something that can be translated into a protocol-specific description of a resource that a client can access directly, such as an fs_location (for NFSv4), or share name (for CIFS). Note that not all FSLs need to be explicitly exported as long as they are contained within an exported path on the fileserver. FSN (Fileset Name): A platform-independent and globally unique name for a fileset. Two FSLs that implement replicas of the same fileset MUST have the same FSN, and if a fileset is migrated from one location to another, the FSN of that fileset MUST remain the same. Lentini, et al. Expires July 25, 2010 [Page 20] Internet-Draft Admin Protocol for Federated Filesystems January 2010 Junction: A filesystem object used to link a directory name in the current fileset with an object within another fileset. The server-side "link" from a leaf node in one fileset to the root of another fileset. Namespace: A filename/directory tree that a sufficiently authorized client can observe. NSDB (Namespace Database) Service: A service that maps FSNs to FSLs. The NSDB may also be used to store other information, such as annotations for these mappings and their components. NSDB Node: The name or location of a server that implements part of the NSDB service and is responsible for keeping track of the FSLs (and related info) that implement a given partition of the FSNs. Referral: A server response to a client access that directs the client to evaluate the current object as a reference to an object at a different location (specified by an FSL) in another fileset, and possibly hosted on another fileserver. The client re-attempts the access to the object at the new location. Replica: A replica is a redundant implementation of a fileset. Each replica shares the same FSN, but has a different FSL. Replicas may be used to increase availability or performance. Updates to replicas of the same fileset MUST appear to occur in the same order, and therefore each replica is self-consistent at any moment. We do not assume that updates to each replica occur simultaneously. If a replica is offline or unreachable, the other replicas may be updated. Server Collection: A set of fileservers administered as a unit. A server collection may be administered with vendor-specific software. The namespace provided by a server collection could be part of the federated namespace. Singleton Server: A server collection containing only one server; a stand-alone fileserver. 9. References Lentini, et al. Expires July 25, 2010 [Page 21] Internet-Draft Admin Protocol for Federated Filesystems January 2010 9.1. Normative References [RFC1094] Nowicki, B., "NFS: Network File System Protocol specification", RFC 1094, March 1989. [RFC1813] Callaghan, B., Pawlowski, B., and P. Staubach, "NFS Version 3 Protocol Specification", RFC 1813, June 1995. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2203] Eisler, M., Chiu, A., and L. Ling, "RPCSEC_GSS Protocol Specification", RFC 2203, September 1997. [RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally Unique IDentifier (UUID) URN Namespace", RFC 4122, July 2005. [RFC4506] Eisler, M., "XDR: External Data Representation Standard", STD 67, RFC 4506, May 2006. [RFC4511] Sermersheim, J., "Lightweight Directory Access Protocol (LDAP): The Protocol", RFC 4511, June 2006. [RFC4513] Harrison, R., "Lightweight Directory Access Protocol (LDAP): Authentication Methods and Security Mechanisms", RFC 4513, June 2006. [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, August 2008. [RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., Housley, R., and W. Polk, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 5280, May 2008. [RFC5531] Thurlow, R., "RPC: Remote Procedure Call Protocol Specification Version 2", RFC 5531, May 2009. 9.2. Informative References [FEDFS-NSDB] Lentini, J., Everhart, C., Ellard, D., Tewari, R., and M. Naik, "NSDB Protocol for Federated Filesystems", draft-ietf-nfsv4-federated-fs-protocol (Work In Progress), 2009. [FEDFS-REQTS] Lentini, et al. Expires July 25, 2010 [Page 22] Internet-Draft Admin Protocol for Federated Filesystems January 2010 Lentini, J., Everhart, C., Ellard, D., Tewari, R., and M. Naik, "Requirements for Federated File Systems", RFC 5716, January 2010. [MS-CIFS] Microsoft Corporation, "Common Internet File System (CIFS) Protocol Specification", MS-CIFS 2.0, November 2009. [MS-SMB] Microsoft Corporation, "Server Message Block (SMB) Protocol Specification", MS-SMB 17.0, November 2009. [MS-SMB2] Microsoft Corporation, "Server Message Block (SMB) Version 2 Protocol Specification", MS-SMB2 19.0, November 2009. [NFSv4.1] Shepler, S., Eisler, M., and D. Noveck, "Network File System (NFS) Version 4 Minor Version 1 Protocol", RFC 5661, January 2010. [NFSv4.1-XDR] Shepler, S., Eisler, M., and D. Noveck, "Network File System (NFS) Version 4 Minor Version 1 External Data Representation Standard (XDR) Description", RFC 5662, January 2010. [RFC3530] Shepler, S., Callaghan, B., Robinson, D., Thurlow, R., Beame, C., Eisler, M., and D. Noveck, "Network File System (NFS) version 4 Protocol", RFC 3530, April 2003. Appendix A. Acknowledgments We would like to thank Paul Lemahieu of EMC, Robert Thurlow of Sun Microsystems, and Mario Wurzl of EMC for helping to author this document. We would also like to thank Trond Myklebust for suggesting improvements to the FSL pathname format and Nicolas Williams for his suggestions. The extract.sh shell script and formatting conventions were first described by the authors of the NFSv4.1 XDR specification [NFSv4.1-XDR]. Lentini, et al. Expires July 25, 2010 [Page 23] Internet-Draft Admin Protocol for Federated Filesystems January 2010 Authors' Addresses James Lentini NetApp 1601 Trapelo Rd, Suite 16 Waltham, MA 02451 US Phone: +1 781-768-5359 Email: jlentini@netapp.com Craig Everhart NetApp 7301 Kit Creek Rd Research Triangle Park, NC 27709 US Phone: +1 919-476-5320 Email: everhart@netapp.com Daniel Ellard BBN Technologies 10 Moulton Street Cambridge, MA 02138 US Phone: +1 617-873-8000 Email: dellard@bbn.com Renu Tewari IBM Almaden 650 Harry Rd San Jose, CA 95120 US Email: tewarir@us.ibm.com Lentini, et al. Expires July 25, 2010 [Page 24] Internet-Draft Admin Protocol for Federated Filesystems January 2010 Manoj Naik IBM Almaden 650 Harry Rd San Jose, CA 95120 US Email: manoj@almaden.ibm.com Lentini, et al. Expires July 25, 2010 [Page 25]