NFS file system attributes for MVS data sets

The z/OS NFS server generates MVS-specific values for certain UNIX file system attributes. Table 1 , Table 2, and Table 3 illustrate the MVS values that the z/OS NFS server generates.

Table 1. File system values to get dynamic file system information
Value	Description	z/OS Conventional MVS Value
tbytes	Total size, in bytes, of the file system	10000000000
fbytes	Amount of free space, in bytes, in the file system	8000000000
abytes	Amount of space, in bytes, available to the user identified by the authentication in the RPC	80000000
tfiles	Total number of file slots in the file system	200000
ffiles	Number of free file slots in the file system	20000
afiles	Number of free file slots that is available to the user corresponding to the authentication information in the RPC	2000
invarsec	Number in seconds for which the file system is not expected to change	0

Table 2. File system values to get static file system information
Value	Description	z/OS Conventional MVS Value
rtmax	Maximum number in bytes for the read request supported by the server	65536 (64KB)
rtpref	Preferred size of the read request	32768 (32KB)
rtmult	Suggested multiple for the size read request	4096
wtmax	Maximum size of a write request supported by the server	65536 (64KB)
wtpref	Preferred size of the write request	32768 (32KB)
wtmult	Suggested multiple for the size of a write request	4096
dtpref	Preferred size of the readdir request	8192
maxfilesize	Maximum size of a file on the system	2 ** 63 - 1
time_delta	File time using setattr	(0,1000000)
Properties:	FSF_LINK FSF_SYMLINK FSF_HOMOGENEOUS FSF_CANSETTIME	1 0 1 1

Table 3. File system values to retrieve POSIX information
Value	Description	z/OS Conventional MVS Value
linkmax	Maximum number of hard links	1
name_max	Maximum length of a component file name (file name + attributes)	255
no_trunc	Server will reject any name that is longer than the name_max	True
chown_restricted	Change either the owner or the group associated with the data set	True
case_insensitive	Server does not distinguish the case when interpreting file names	True
case_preserving	If True, the server file system will preserve the case of a name during a create, mkdir, mknod, symlink, rename, or link	False