FILESYNC= System Option

Specifies when operating system buffers that contain contents of permanent SAS files are written to disk.
Valid in: Configuration file, SAS invocation
Category: Files: SAS Files
PROC OPTIONS GROUP= SASFILES
Note: This option can be restricted by a site administrator. For more information, see Restricted Options.
See: FILESYNC= System Option: z/OS in SAS Companion for z/OS

Syntax

FILESYNC= SAS | CLOSE | HOST | SAVE

Syntax Description

SAS
specifies that SAS requests the operating system to force buffered data to be written to disk when it is best for the integrity of the SAS file.
CLOSE
specifies that SAS requests the operating system to force buffered data to be written to disk when the SAS file is closed.
HOST
specifies that the operating system schedules when the buffered data for a SAS file is written to disk. This is the default.
SAVE
specifies that the buffers are written to disk when the SAS file is saved.

Details

By using the FILESYNC= system option, SAS can tell the operating system when to force data that is temporarily stored in operating system buffers to be written to disk. Only SAS files in a permanent SAS library are affected; files in a temporary library are not affected.
If you specify a value other than the default value of HOST, the following occurs:
  • the length of time it takes to run a SAS job increases
  • the small chance of loosing data in the event of a system failure is further reduced
Consult with your system administrator before you change the value of the FILESYNC= system option to a value other than the default value.
z/OS Specifics: Under z/OS, the FILESYNC= system option affects SAS files only in UNIX file system (UFS) libraries. For more information, see FILESYNC= System Option: z/OS in SAS Companion for z/OS.