NFS protocol attributes

Table 1 provides general reference information about the z/OS NFS server's support of NFS protocol attributes. To determine which attributes are communicated between the client and server for the version of the NFS protocol that you are using, see the corresponding RFC at the Internet Engineering Task Force (IETF) home page http://www.ietf.org/ :

NFS protocol version 2: RFC 1094
NFS protocol version 3: RFC 1813
NFS protocol version 4: RFC 3530.

Table 1. NFS Version 4 Attributes
Num	Attribute Name	Supp_attr value (Note 1, 5)	Comments (Note 2)
1	type	1	File object type (File, Directory, Link, etc.) (Note 5) UNIX value: at_mode, NFALL_B MVS value: NFS generated
2	fh_expire_type	1	Indicates a file handle is persistent or volatile across server restarts. (Note 5) UNIX value: NFSV4 fh4_volatile_any MVS value: NFSV4 fh4_volatile_any
3	change	1	Server generated value which is updated when an NFS object attribute or content changes. UNIX value: at_ctime64, at_ctimemsec MVS value: NFS server generated (Notes 4, 5)
4	size	1	Object size in bytes. UNIX value: at_size or 512 if an empty directory (Note 5) MVS value: (Note 3)
5	link_support	1	Objects file system supports hard links (Note 5) UNIX value: fs_nfsprop.fs_fsf_link MVS value: 0 (not supported)
6	symlink_support	1	Objects file system supports symbolic links (Note 5) UNIX value: fs_nfsprop.fs_fsf_symlink MVS value: 0 (not supported)
7	named_attr	1	Object has named attributes (Note 5) UNIX value: 0 (not supported) MVS value: 0 (not supported)
8	fsid	1	Unique file system id (Note 5) UNIX value: at_dev MVS value: (Note 8)
9	unique_handles	1	Distinct file handles are guaranteed to represent different objects. UNIX value: 0 MVS value: 0
10	lease_time	1	Duration of lease in seconds. UNIX value: NFS server site attribute. MVS value: NFS server site attribute
11	rdattr_error	1	Readattr error during getattr operation.UNIX value: error enum MVS value: error enum
12	ACL	UNIX: 1 MVS: 0	Object's associated access control list UNIX value: Object's ACL values MVS value: undefined
13	aclsupport	1	Types of ACLs supported by the server UNIX value: 1 MVS value: 0
14	archive	0	Object has been archived since last modification. UNIX value: undefined MVS value: undefined
15	cansettime	1	Server is able to change times as specified in a setattr UNIX value: fs_nfsprop.fs_fsf_CanSetTime MVS value: 1
16	case_insensitive	1	Server file name comparisons are case insensitive. (Note 5) UNIX value: pcfgcaseinsensitive MVS value: 1
17	case_preserving	1	Filename case is persevered on this file system. UNIX value: pcfgcaseonpreserving MVS value: 0
18	chown_restricted	1	Changes to file owner or group requires privileged user. (Note 5) UNIX value: 0 MVS value: 1
19	filehandle	1	Objects associated file handle. (Note 5) UNIX value: NFS server generated MVS value: NFS server generated
20	fileid	1	A number uniquely identifying the file on this file system. (Notes 5, 7) UNIX value: BPXYATTR.AttrFid MVS value: NFS server generated
21	files_avail	1	Available file slots. (Note 5) UNIX value: fs_favail MVS value: 2,000
22	files_free	1	Free file slots. (Note 5) UNIX value: fs_ffree MVS value: 20,000
23	files_total	1	Total file slots. (Note 5) UNIX value: fs_files MVS value: 200,000
24	fs_locations	0	Alternate locations where this file system may be found. UNIX value: undefined MVS value: undefined
25	hidden	0	Hidden file with respect to the Windows API. UNIX value: undefined MVS value: undefined
26	homogeneous	1	file system attributes are the same for all objects within the file system. UNIX value: fs_nfsprop.fs_fsf_homogeneous MVS value:1
27	maxfilesize	1	Maximum file size. (Notes 3, 5) UNIX value: fs_maxfilesize MVS value: see notes.
28	maxlink	1	Maximum number of links for this object. (Note 5) UNIX value: pcfglinkmax MVS value: 1
29	maxname	1	Maximum filename size for this object. (Note 5) UNIX value: pcfgnamemax MVS value: 256
30	maxread	1	Maximum read size for this object. (Note 5) UNIX value: 65536MVS value: 65536
31	maxwrite	1	Maximum write size for this object. (Note 5) UNIX value: 65536 MVS value: 65536
32	mimetype	0	MIME body type/subtype for this object. UNIX value: undefined MVS value: undefined
33	mode	1	Support of UNIX-style mode and permission bits. (Note 5) UNIX value: at_mode MVS value: 666 or 777
34	no_trunc	1	Return error rather than truncate the filename if name is greater than maxname. UNIX value: pcfgnotrunc MVS value: 1
35	numlinks	1	Number of hard links to this object. (Note 5) UNIX value:at_nlink MVS value: file = 1, directory = 2
36	owner	1	The owner's string name. (Note 9) UNIX value: undefined. MVS value: undefined..
37	owner_group	1	The owner's group string name. (Note 9) UNIX value: undefined. MVS value: undefined.
38	quota_avail_hard	0	Server rejects a write request and provides the additional disk space that can be allocated to this file or directory. UNIX value: undefined. MVS value: undefined.
39	quota_avail_soft	0	Server reasonably warns on a write request and provides the additional disk space that can be allocated to this file or directory. UNIX value: undefined. MVS value: undefined.
40	quota_used	0	Amount of disk space used by this file or directory. UNIX value: undefined. MVS value: undefined.
41	rawdev	UNIX: 1 MVS: 0	Raw USS device identifier (UNIX device major/minor node information). UNIX value: at_major, at_minor MVS value: undefined.
42	space_avail	1	Disk space available to this user. (Notes 3, 5) UNIX value: fs_freespace, fs_blocksize MVS value: 80,000,000
43	space_free	1	Filesystem free disk space. (Notes 3, 6) UNIX value: fs_freespace, fs_blocksize MVS value: 8,000,000,000
44	space_total	1	Filesystem total disk space. (Notes 3, 5) UNIX value: fs_usedspace, fs_blocksize MVS value: 10,000,000,000
45	space_used	1	Allocated bytes for this file object. (Notes 3, 6) UNIX value: at_blocksh, at_blocks, at_blksize MVS value: see notes.
46	system	0	System file with respect to the Windows API. UNIX value: undefined. MVS value: undefined.
47	time_access	1	Last read access satisfied by server for this object. (Notes 4, 5, 6) UNIX value: at_atime64 MVS value: see notes.
48	time_access_set	1	Setattr operation to set the time of last access for this object. (Notes 4, 5, 6) UNIX value: at_atimechg, at_atimeTOD MVS value: support is limited, see notes.
49	time_backup	0	Last backup time for this object. UNIX value: undefined. MVS value: undefined.
50	time_create	UNIX: 1 MVS: 0	Object time of creation. (Notes 4, 6) UNIX value: at_createtime64 MVS value: undefined.
51	time_delta	1	Smallest useful server time granularity. (Notes 4, 5) UNIX value: fs_time_delta_sec, fs_time_delta_ns MVS value: 1 second.
52	time_metadata	UNIX: 1 MVS: 0	Time of last meta-data modification to the object. (Note 4) UNIX value: at_ctime64,at_ctimemsec MVS value: undefined.
53	time_modify	1	Time of last modification to the object. (Notes 4, 6) UNIX value: at_mtime64 MVS value: see notes.
54	time_modify_set	1	Setattr operation to set the time of last modification for this object. (Notes 4, 5, 6) UNIX value: at_mtimechg, at_mtimeTOD MVS value: see notes.
55	mounted_on_fileid	UNIX: 1 MVS: 0	Like fileid, but if the target filehandle is a file system root the fileid of the underlying file system directory is returned. UNIX value: undefined. MVS value: same as fileid.

Note:

Column indicates z/OS NFS server V4 supp_attr attribute setting, where 0 = no support, 1 = supported values. The NFS V4 supp_attr is a bitmap of attributes requested, returned, or being set in an NFS client request.
UNIX value may contain the UNIX system provided macro and field name. For additional information on UNIX values see z/OS UNIX System Services File System Interface Reference.
See z/OS DFSMS Using Data Sets for additional information on MVS file size limits. See File size value for MVS data sets and sections Creating physical sequential files, Creating direct access files, and Creating PDSs and PDSEs for additional information on file sizes.
For z/OS conventional MVS data sets refer to handling of time stamps in Time stamps for MVS data sets.
The constant or generated values are being provided by the NFS server for performance or correct operation.
For z/OS conventional MVS data sets, values represent those in the data set control block DSCB, Catalog locate, PDSE directory, HSM MIC cell, and SMS DATACLASS.
The fileid of z/OS conventional MVS data sets is generated from data set name and member name using crc32 checksum algorithms.
Returned by z/OS UNIX System Services as a result of the NFS server registration request v_reg() during server initialization.
The z/OS NFS server supports name@domain owner and owner_group strings in this release. These strings are the string name of the owner of file system object and the string name of the group ownership of file system object. The strings are returned and accepted for setattr, verify, nverify, open, create, getattr, and readdir.