HADB File System Support

There are several important considerations if you want to configure HADB to use one of the following file systems:

• ext2 and ext3– HADB supports ext2 and ext3 file systems for Red Hat Application Server 3.0. For Red Hat Application Server 2.1, HADB supports only the ext2 file system.

• Veritas– When the Veritas File System is used on the Solaris platform, the message “WRN: Direct disk I/O mapping failed“ is written to the history files. This message indicates that HADB cannot turn on direct I/O for the data and log devices. Direct I/O is a performance enhancement that reduces the CPU cost of writing disk pages. It also causes less overhead of administering dirty data pages in the operating system.

  To use direct I/O with the Veritas File System, use one of the following:

  • Create the data and log devices on a file system that is mounted with the option mincache=direct. This option applies to all files created on the file system. See the mount_vxfs(1M) command for details.

  • Use the Veritas Quick I/O facility to perform raw I/O to file system files. See the VERITAS File System 4.0 Administrator's Guide for Solaris for details.

    Note that these configurations have not been tested with Application Server 8.2 .

    Refer to the Application Server Enterprise Edition High Availability Administration Guide for information about installing and configuring HADB with Application Server software.