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 any temporary library are not affected. The FILESYNC= system option
affects only SAS files in UFS libraries.
For direct access bound
libraries and sequential access bound libraries, updates to files
are performed as if FILESYNC=SAS has been specified, regardless of
the setting of the FILESYNC option.
The HSSAVE system option,
not FILESYNC, controls the timing for file updates to be committed
to disk for members of DIV libraries. When the HSSAVE option is in
effect, processing is equivalent to FILESYNC=SAS being in effect.
The FILESYNC option has no effect on processing for DIV libraries.