Enable NO FILE SYSTEM CACHING for DB2 on System z
When the operating system is Linux on System z , enable the NO FILE SYSTEM CACHING option for IBM DB2 databases to improve performance.
Important: Enable the NO FILE SYSTEM CACHING option on an unsupported device could cause the database to become inaccessible. Ensure the file system supports the NO FILE SYSTEM CACHING option and that it meets the requirements for creating table spaces without file system caching.
- Create a backup copy of the DB2 database using native database tools.
- If the database server and Connections are installed on different systems, copy the SQL scripts to the system hosting the database server.
- The SQL scripts for DB2 for Linux on System z are located in the connections.s390.sqlapplication directory of the Connections set-up directory or installation media, where application is the directory containing the SQL scripts for each application.
- We can enable the NO FILE SYSTEM CACHING option for the Activities, Communities, and Profiles databases only.
When you create DB2 databases for Connections under Linux on System z, the database wizard and the createDb.sql script create table spaces with the FILE SYSTEM CACHING option enabled. If we are storing DB2 table spaces on devices where Direct I/O (DIO) is enabled, such as Small Computer System Interface (SCSI) disks that use Fibre Channel Protocol (FCP), we can improve database performance by enabling the NO FILE SYSTEM CACHING option.
To enable the NO FILE SYSTEM CACHING option:
- Log in to the DB2 database system with the user ID of our owner of the database instance. The user ID must have privileges to create a database, a table space, tables, and indexes.
If we created multiple database instances, specify the user ID for the first instance.
- Enable the NO FILE SYSTEM CACHING option for the Activities table space by entering the following commands:
CONNECT TO OPNACT
ALTER TABLESPACE OAREGTABSPACE NO FILE SYSTEM CACHING
CONNECT RESET
- Enable the NO FILE SYSTEM CACHING option for the Communities table space by entering the following commands:
CONNECT TO SNCOMM
ALTER TABLESPACE SNCOMMREGTABSPACE NO FILE SYSTEM CACHING
ALTER TABLESPACE DFREGTABSPACE NO FILE SYSTEM CACHING
CONNECT RESET
- Enable the NO FILE SYSTEM CACHING option for the Forums table space by entering the following commands:
CONNECT TO FORUM
ALTER TABLESPACE DFREGTABSPACE NO FILE SYSTEM CACHING
CONNECT RESET
- Enable the NO FILE SYSTEM CACHING option for the Profiles table space by entering the following commands:
CONNECT TO PEOPLEDB
ALTER TABLESPACE USERSPACE4K NO FILE SYSTEM CACHING
ALTER TABLESPACE TEMPSPACE4K NO FILE SYSTEM CACHING
ALTER TABLESPACE USERSPACE32K NO FILE SYSTEM CACHING
ALTER TABLESPACE TEMPSPACE32K NO FILE SYSTEM CACHING
CONNECT RESET
- Close the DB2 command line processor.
Parent topic:
Create databases
Related:
Create IBM DB2 databases manually
Update 4.0 and 4.5 databases with the wizard
Update 4.0 and 4.5 DB2 databases manually
Related reference: