Informix Error -21533: Defragment: A defragmentation task is already in progress on this dbspace.

Reasons / Common Causes

-21533 fires when a second defragmentation task is requested on a dbspace that already has one running — per the official guidance.

1. A defragmentation task already running on the target dbspace, per the official guidance — the direct, only cause.

Solutions / Resolution

1. Run only one defragmentation task per dbspace at a time, per the official guidance — wait for the running one to finish.

Examples

N/A

No specific triggering statement is documented beyond overlapping defragmentation tasks on one dbspace.

Diagnostic Checks

1. Check for an already-running defragmentation task on the dbspace, and wait for it to complete.

Related Errors / Related Topics

• -21528 — "Defragment: The partition does not require defragmentation." A related defragmentation condition, on fragmentation level rather than a concurrent task.
• -21537 — "Defragment: This command cannot be run while a defragmentation is in progress." A related concurrency restriction, for a different command class blocked by an in-progress defragment.

A defragmentation task was already running on the dbspace — wait for it to finish before starting another.