If you need to disable Concurrent I/O, use the DB2 file system caching option.
Note:
If you used the namefs -o cio option with the mountcommand to mount a directory to enable Concurrent I/O, make sure you remount without that option as well. Also, if you follow the directions for enabling Concurrent I/O on an existing SMS container, rename the directory back to the original name.
To disable Concurrent I/O on a DB2 tablespace
Use the DB2 file system caching option as follows:
# db2 -v "alter tablespace tablespace_name file system caching"
where tablespace_name is the name of the tablespace for which you are disabling Concurrent I/O.
