ANR2568E for node to start schedule is denied

Answer

If two or more CAD instances are running against the same schedule for the same node then both could attempt to run the same schedule within the same window. While the first schedule should start without a problem, the second would fail with the ANR2568E as the first has now set the next scheduled execution for a future point in time.

In the example schedule log output, the CAD daemon is running on a 4 hour period checking for the next scheduled operation. At 11:46:09 a second CAD daemon is started that picks up the same schedule. The entries that follow show these two CAD instances interwoven. Once the second CAD started the scheduler for the second attempt at the same schedule the ANR2568E is produced on the Tivoli Storage Manager server.

11/07/12 05:21:47 (dsmcad) Time remaining until execution:
Executing scheduled command now.
11/07/12 09:21:57 (dsmcad) Next operation scheduled:
11/07/12 09:21:57 (dsmcad) ------------------------------------------------------------
11/07/12 09:21:57 (dsmcad) Schedule Name: SCHED1
11/07/12 09:21:57 (dsmcad) Action: Incremental
11/07/12 09:21:57 (dsmcad) Objects:
11/07/12 09:21:57 (dsmcad) Options:
11/07/12 09:21:57 (dsmcad) Server Window Start: 01:00:00 on 11/08/12
11/07/12 09:21:57 (dsmcad) ------------------------------------------------------------
11/07/12 09:21:57 (dsmcad) Command will be executed in 4 hours
.
11/07/12 09:21:57 (dsmcad) Time remaining until execution:
11/07/12 11:46:09 (dsmcad) IBM Tivoli Storage Manager
11/07/12 11:46:09 (dsmcad) Client Acceptor - Built Mar 6 2012 18:22:29
11/07/12 11:46:09 (dsmcad) Version 6, Release 3, Level 0.0
11/07/12 11:46:09 (dsmcad) ANS3000I TCP/IP communications available on port 39057.
11/07/12 11:46:09 (dsmcad) Dsmcad is working in Schedule mode.
11/07/12 11:46:09 (dsmcad) Command will be executed in 1 minute.
11/07/12 11:46:09 (dsmcad) Time remaining until execution:
Executing scheduled command now.
11/07/12 11:47:19 (dsmcad) Next operation scheduled:
11/07/12 11:47:19 (dsmcad) ------------------------------------------------------------
11/07/12 11:47:19 (dsmcad) Schedule Name: SCHED1
11/07/12 11:47:19 (dsmcad) Action: Incremental
11/07/12 11:47:19 (dsmcad) Objects:
11/07/12 11:47:19 (dsmcad) Options:
11/07/12 11:47:19 (dsmcad) Server Window Start: 01:00:00 on 11/08/12
11/07/12 11:47:19 (dsmcad) ------------------------------------------------------------
11/07/12 11:47:19 (dsmcad) Command will be executed in 4 hours
.
11/07/12 11:47:19 (dsmcad) Time remaining until execution:
Executing scheduled command now.
11/07/12 13:22:07 (dsmcad) Next operation scheduled:
11/07/12 13:22:07 (dsmcad) ------------------------------------------------------------
11/07/12 13:22:07 (dsmcad) Schedule Name: SCHED1
11/07/12 13:22:07 (dsmcad) Action: Incremental
11/07/12 13:22:07 (dsmcad) Objects:
11/07/12 13:22:07 (dsmcad) Options:
11/07/12 13:22:07 (dsmcad) Server Window Start: 01:00:00 on 11/08/12
11/07/12 13:22:07 (dsmcad) ------------------------------------------------------------
11/07/12 13:22:07 (dsmcad) Command will be executed in 4 hours

To avoid this problem ensure that only one CAD instance is started for each nodename for a given schedule.