The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.
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. You should also specify the
datavolume
mount option for the 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 avoid database blocks becoming fragmented across a disk,
ensure that the file system cluster size is at least as big as
the database block size, which is typically 8KB. If you specify
the file system usage type as datafiles
to
the mkfs.ocfs2 command, the file system
cluster size is set to 128KB.
To allow multiple 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, but OCFS2 does
not 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 in different nodes reporting
different time stamps for the same file. You can use the
following command to view the on-disk timestamp of a file:
# debugfs.ocfs2 -R "stat /file_path
" device
| grep "mtime:"