EFSO - extended file system options.

Description:

The following options are accepted by the ACCESS CF and MF functions. The SLOCK and NSLOCK options may also be applied to the CC and MC functions. For a detailed description of these functions, see the "File Management Supervisor" manual.

With the possible exceptions of SLOCK, NSLOCK, and WLOCK, these options are intended for database files used in batch, or by a transaction processor. A TSS user will not normally use them.

SLOCK

puts a security lock on a file or catalog. A security lock provides an additional level of access control. To access a security locked file, you must have both the desired permission to access and permission to pass the security lock.

NSLOCK

removes a security lock from a file or catalog.

WLOCK

puts a write lock on a file. From this point onwards, the file may only be accessed for reading. There is no way to remove a write lock -- if you want to get rid of it, make a copy of the file, release the original, and recreate a new version of the file using the copy.

SAVE

saves file content whenever it is a candidate for saving.

NSAVE

specifies that the file contents should not be saved. Although this request is NOT honored by the current FMS save programs, there is a small chance that it will be honored in the future, so NSAVE should only be specified for files for which an alternate backup procedure exists.

ABORT/x/

specifies what to do when a job aborts while writing the file. "x" may be one of LOCK, ARCHIVE, ROLLBACK or NONE. NONE is the default on file create.

ACCESS/x/

specifies how many users can read and write a file simultaneously. "x" may be one of NORMAL, RWW, CONCURRENT, or MONITOR.

NORMAL: a writer never shares the file with anyone. ACCESS creates files this way by default.
RWW: one writer may share the file with readers that request concurrent access. Requests for write access are assumed to be concurrent requests, unless private ("p") access is explicitly requested. B, C and PASCAL programs create files with RWW (read while writing) access control.
CONCURRENT: Multiple writers and readers can share the file provided they all specify concurrent access.
MONITOR: This is like CONCURRENT, but the use of the file is monitored by the system which will allow the program to lock and unlock pieces of the file. Such files cannot be accessed concurrently in TSS.

This discussion ignores query readers who can share a file no matter how it is being used by anyone else.

AUDIT/x/

determines what allocation requests should be logged on the accounting file. "x" may be one of ALL, DENIED, or NONE. The default is NONE.

INCRSAVE/x/

If "x" is NO, the file will not be saved by an incremental save, even if it is a candidate for saving. The default is YES.

PAGESIZE/nnn/

"nnn" is an integer such that 40 <= nnn <= 3840. The default is 320.

RDERR/x/

specifies what action to should be taken to guard against a disk or part of the disk with this file failing. "x" can be one of NONE, DUP, or JOURNAL.

NONE: is the normal case. Since disks fail so seldom you simply depend on restoring the data from the last save.
DUP or DUP:ddd: the system will maintain two physical copies of the file. If one is unreadable, the system will use the copy. This can only be specified when creating a file. The form "DUP:ddd" specifies a specific device for the duplicate copy.
JOURNAL: All changes to the file are logged to a journal file or tape so that the file can be restored to its state at the time when the disk failed. Such a file can only be accessed with LOAD permission (no journalling) in TSS.

DUP and JOURNAL may both be specified for a file.

VERIFY/x/

"x" may be YES or NO. NO is the default. If YES is specified, the system will read back after every write to verify that it was written correctly.