Oracle Database Use Case

Note:

Check the Oracle Database installation documentation for Linux to verify that the platform is certified for use with the current Oracle Linux release: https://docs.oracle.com/en/database/oracle/oracle-database/index.html.

Specify the noatime option when mounting volumes that host Oracle datafiles, control files, redo logs, voting disk, and OCR. The noatime option disables unnecessary updates to the access time on the inodes.

Specify the nointr mount option to prevent signals interrupting I/O transactions that are in progress.

By default, the init.ora parameter filesystemio_options directs the database to perform direct I/O to the Oracle datafiles, control files, and redo logs. Specify the datavolume mount option for volumes that contain the voting disk and OCR. Do not specify this option for volumes that host the Oracle user's home directory or Oracle E-Business Suite.

To prevent database blocks from becoming fragmented across a disk, ensure that the file system cluster size is at least as large as the database block size, which is typically 8KB. If you specify the file system usage type as datafiles when using the mkfs.ocfs2 command, the file system cluster size is set to 128KB.

To enable many nodes to maximize throughput by concurrently streaming data to an Oracle datafile, OCFS2 deviates from the POSIX standard by not updating the modification time (mtime) on the disk when performing non-extending direct I/O writes. The value of mtime is updated in memory. However, OCFS2 doesn't write the value to disk unless an application extends or truncates the file or performs a operation to change the file metadata, such as using the touch command. This behavior leads to results with different nodes reporting different time stamps for the same file. Use the following command to view the on-disk timestamp of a file:

sudo debugfs.ocfs2 -R "stat /file_path" device | grep "mtime:"