Enabling Asynchronous Disk I/O HP-UX

To improve I/O performance on character or raw and block devices, enable asynchronous I/O by installing the HP asynchronous I/O driver from SAM.

  1. Shut down SAP ASE.
  2. From the SAM Kernel Configuration menu, choose Drivers and set the pending state for asyncdisk to In by adding the driver. Alternatively, add the asyncdisk subsystem keyword to /stand/system.
  3. Rebuild the kernel, and restart the system.
  4. Using the userid root, execute:
    #/etc/mknod/dev/async c 101 4
    #chmod 0660/dev/async
    #chown <uid> /dev/async
    #/etc/setprivgrp <ugrp> MLOCK


    • <uid> is the identification (user ID) used by the user who is restarting SAP ASE. This user must be the owner of the /dev/async directory.
    • <ugrp> is the user group for the <uid> user ID.