Enabling Asynchronous IO at HP-UX Operating System We are using HP-UX Itanium version B.11.31 and this server is used for running Sybase database version ASE15.7. I would like to know how to enable Asynchronous IO at Operating System level. I went through Sybase ASE and their suggestion is provided at this link. ![Sybase Asynchronous IO]( Appreciate your valuable input as which one should be chosen. I feel it should be "Enabling Asynchronous I/O for File System Devices." Database is stored in the file system and they are VxFS(Veritas File System)

Looks like the three pages are somewhat poorly titled.

"Enabling Asynchronous Disk I/O HP-UX" page describes the installation of the asynchronous I/O driver. It would be definitely needed if you wanted to use asynchronous I/O with raw devices, but you aren't planning to do that.

I found this link to an old HP Knowledge Mine document that confirms that the `asyncdisk` driver is for raw disk access only.

"Enabling Asynchronous I/O for File System Devices" page describes a pair of HP-UX kernel tunables as a prerequisite, but the actual task seems to be _how to enable Sybase to **use** HP-UX asynchronous file I/O_, assuming it's available.

"Enabling Asynchronous I/O for File Systems" page describes how to make sure HP-UX can **provide** asynchronous file I/O. It says "you need to have OnlineJFS installed". Basically, this page should have been a part of the "prerequisites" section of the previous page.