The directio parameter allows you to configure Adaptive Server to transfer data directly to disk, bypassing the operating system buffer cache. directio performs IO in the same manner as raw devices and provides the same performance benefit as raw devices, but has the ease of use and manageability of file system devices. You cannot set the directio option for the master device. directio is a static parameter that requires a restart of Adaptive Server to take effect .
This article describes how to change the device attribute from ‘dsync’ to ‘directio’.
Device attributes can be changed by calling the sp_deviceattr procedure twice, first to disable dsync and second to enable directio:-
sp_deviceattr , 'dsync', false
sp_deviceattr , 'directio', true