When Can You Change ontape Parameters?

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When Can You Change ontape Parameters?

You can change the values of parameters for ontape while the database server is online. The change takes effect immediately.

Note:

If you want to set either the TAPEDEV parameter or the LTAPEDEV parameter to /dev/null, you must use the ON-Monitor utility to make this change while the database server is online. If you use any other method to alter the value of the configuration parameters to or from /dev/null, you must restart the database server to make the change effective.

Changing TAPEDEV to /dev/null

The ontape utility reads the value of the TAPEDEV parameter at the start of processing. When you set TAPEDEV to /dev/null and request a backup, the database server bypasses the backup but still updates the dbspaces with the new backup time stamps. When you set TAPEDEV to /dev/null, you must do it before you start ontape to request the backup. No problems exist when you change TAPEDEV to /dev/null with ON-Monitor while the database server is online and ontape is not running.

Changing LTAPEDEV to /dev/null

Take the database server offline before you change the value of LTAPEDEV to /dev/null. When you make the change while the database server is either quiescent or online, you can create a situation where you back up one or more logical-log files but do not free them. This situation can interrupt processing because the database server stops when it finds that the next logical-log file (in sequence) is not free.

When you set LTAPEDEV to /dev/null, the database server frees the logical logs without requiring that you back up those logs. The logical logs do not get marked as free, but the database server can reuse them.

Verifying That the Tape Device Can Read the Specified Block Size

The ontape utility does not check the tape device when you specify the block size. Verify that the tape device specified in TAPEDEV and LTAPEDEV can read the block size you specify for their block-size parameters. If not, you cannot restore the tape.