The dsync Parameter

The dsync parameter ensures SAP ASE can recover data from devices on file systems.

By default, SAP ASE disables dsync for file system devices. However, dsync may cause performance degradation for file system devices that experience high write activity. You can set or reset dsync using the disk init, disk reinit, and sp_deviceattr commands. When dsync is set to false (off), cached I/O is used.

Note: dsync and directio are ignored for raw devices.

Immediately after upgrading, make sure that either dsync or directio is set for the file system devices. See also sp_deviceattr and sp_helpdevice in the Reference Manual: Procedures

Related concepts
The directio Parameter