Checkpoint never return! HELP!

Hi, I got a fatal error that cause my DB crash. the following is from online.log, which shows the "Checkpoint never return!!" please see: ******************************************** 10:31:02 Logical Log 93549 - Backup Started 10:52:41 INFORMIX-OnLine Stopped. Fri Sep 20 10:53:22 1996 and 11:14:41 Logical Log 93866 - Backup Started 11:56:46 INFORMIX-OnLine Stopped. Sat Sep 21 11:58:28 1996 ******************************************** So I have to bring the db down (The line with INFORMIX-OnLine Stopped.) What reason can cause the checkpoint never return? the strage is it happened almost once every 24 hrs. What is the procedures I should do to analyse the problem? LRU? memory? Please help! It's ergent! PS. The DR is because we have two servers, u3hsrv2 and u3hsrv3. using INFORMIX 7.12 and HP-UX A.09.04 U 9000/887 10:10:18 Logical Log 93544 - Backup Started 10:10:19 Logical Log 93544 - Backup Completed 10:13:14 Checkpoint Completed: duration was 1 seconds. 10:14:47 Logical Log 93545 Complete. 10:14:49 Logical Log 93545 - Backup Started 10:14:54 Logical Log 93545 - Backup Completed 10:18:15 Checkpoint Completed: duration was 1 seconds. 10:21:28 Logical Log 93546 Complete. 10:21:28 Logical Log 93546 - Backup Started 10:21:30 Logical Log 93546 - Backup Completed 10:23:17 Checkpoint Completed: duration was 1 seconds. 10:25:12 Logical Log 93547 Complete. 10:25:15 Logical Log 93547 - Backup Started 10:25:16 Logical Log 93547 - Backup Completed 10:28:17 Logical Log 93548 Complete. 10:28:19 Checkpoint Completed: duration was 1 seconds. 10:28:21 Logical Log 93548 - Backup Started 10:28:22 Logical Log 93548 - Backup Completed 10:30:58 Logical Log 93549 Complete. 10:31:02 Logical Log 93549 - Backup Started 10:52:41 INFORMIX-OnLine Stopped. Fri Sep 20 10:53:22 1996 10:53:22 DR: DRAUTO is 0 (Off) 10:53:23 INFORMIX-OnLine Initialized -- Shared Memory Initialized. 10:53:23 DR: Trying to connect to secondary server ... 10:53:26 DR: Primary server connected 10:53:26 DR: Receive error 10:53:26 DR: Failure recovery error (2) 10:53:27 Physical Recovery Started. 10:53:27 DR: Turned off on primary server 10:53:28 Physical Recovery Complete: 992 Pages Restored. 10:53:28 Logical Recovery Started. 10:53:40 Checkpoint Completed: duration was 3 seconds. 10:53:40 DR: Cannot connect to secondary server 10:53:40 Logical Recovery Complete. 101 Committed, 1 Rolled Back, 0 Open, 0 Bad Locks 10:53:40 Dataskip is now OFF for all dbspaces 10:53:40 On-Line Mode 10:53:41 Checkpoint Completed: duration was 1 seconds. 10:53:50 DR: Primary server connected 10:53:50 DR: Receive error 10:53:50 DR: Failure recovery error (2) 10:53:51 DR: Turned off on primary server 10:53:52 Checkpoint Completed: duration was 0 seconds. 10:53:52 DR: Cannot connect to secondary server 10:54:03 DR: Primary server connected 10:54:03 DR: Receive error 10:54:03 DR: Failure recovery error (2) 10:54:04 DR: Turned off on primary server 10:54:05 Checkpoint Completed: duration was 0 seconds. 10:54:05 DR: Cannot connect to secondary server 10:54:16 DR: Primary server connected 10:54:16 DR: Receive error 10:54:16 DR: Failure recovery error (2) 10:54:17 DR: Turned off on primary server 10:54:18 Checkpoint Completed: duration was 0 seconds. 10:54:18 DR: Cannot connect to secondary server 10:54:29 DR: Primary server connected 10:54:29 DR: Receive error 10:54:29 DR: Failure recovery error (2) 10:54:30 DR: Turned off on primary server 10:54:31 Checkpoint Completed: duration was 0 seconds. 10:54:31 DR: Cannot connect to secondary server 10:54:41 DR: Primary server connected 10:54:42 DR: Receive error 10:54:42 DR: Failure recovery error (2) 10:54:42 DR: Turned off on primary server 10:54:43 Checkpoint Completed: duration was 0 seconds. 10:54:43 DR: Cannot connect to secondary server 10:54:53 DR: Primary server connected 10:54:53 DR: Receive error 10:54:53 DR: Failure recovery error (2) 10:54:55 DR: Turned off on primary server 10:54:56 Checkpoint Completed: duration was 0 seconds. 10:54:56 DR: Cannot connect to secondary server 10:55:06 DR: Primary server connected 10:55:06 DR: Receive error 10:55:06 DR: Failure recovery error (2) 10:55:08 DR: Turned off on primary server 10:55:09 Checkpoint Completed: duration was 0 seconds. 10:55:09 DR: Cannot connect to secondary server 10:56:20 DR: Primary server connected 10:56:21 DR: Sending log 93549, size 500 pages, 100.00% used 10:56:29 DR: Sending log 93550, size 500 pages, 38.40% used 10:56:29 Logical Log 93550 Complete. 10:56:30 DR: Sending log 93551 (current), size 500 pages, 0.00% used 10:56:30 DR: Sending Logical Logs Completed 10:57:00 DR: Primary server operational 10:57:00 DR: LBU_PRESERVE turned on while primary 10:57:02 Checkpoint Completed: duration was 0 seconds. 11:00:14 Logical Log 93551 Complete. 11:01:43 Logical Log 93552 Complete. 11:02:12 Checkpoint Completed: duration was 1 seconds. 11:02:55 Logical Log 93553 Complete. 11:03:56 Logical Log 93554 Complete. 11:05:40 Logical Log 93555 Complete. 11:07:14 Checkpoint Completed: duration was 2 seconds. 11:07:40 Logical Log 93556 Complete. 11:09:20 Logical Log 93557 Complete. 11:10:43 Logical Log 93558 Complete. 11:12:16 Checkpoint Completed: duration was 2 seconds. 11:12:31 Logical Log 93559 Complete. 11:13:36 Logical Log 93560 Complete. 11:15:28 Logical Log 93561 Complete. 11:16:54 Logical Log 93562 Complete. 11:17:19 Checkpoint Completed: duration was 3 seconds. 11:18:22 Logical Log 93563 Complete. 11:19:25 Logical Log 93549 - Backup Started 11:19:26 Logical Log 93549 - Backup Completed 11:19:26 Logical Log 93550 - Backup Started 11:19:27 Logical Log 93550 - Backup Completed 11:19:27 Logical Log 93551 - Backup Started 11:19:32 Logical Log 93551 - Backup Completed 11:19:32 Logical Log 93552 - Backup Started 11:19:34 Logical Log 93552 - Backup Completed 11:19:34 Logical Log 93553 - Backup Started 11:19:37 Logical Log 93553 - Backup Completed 11:19:37 Logical Log 93554 - Backup Started 11:19:39 Logical Log 93554 - Backup Completed 11:19:39 Logical Log 93555 - Backup Started 11:19:42 Logical Log 93555 - Backup Completed 11:19:42 Logical Log 93556 - Backup Started 11:19:44 Logical Log 93556 - Backup Completed 11:19:44 Logical Log 93557 - Backup Started 11:19:47 Logical Log 93557 - Backup Completed 11:19:47 Logical Log 93558 - Backup Started 11:19:49 listener-thread: err = -956: Client host or user (mes@u3hsrv2) is not trusted by the server. 11:19:49 Logical Log 93558 - Backup Completed 11:19:50 Logical Log 93559 - Backup Started 11:19:52 Logical Log 93559 - Backup Completed 11:19:52 Logical Log 93560 - Backup Started 11:19:54 Logical Log 93560 - Backup Completed 11:19:54 Logical Log 93561 - Backup Started 11:19:57 Logical Log 93561 - Backup Completed 11:19:57 Logical Log 93562 - Backup Started 11:19:59 Logical Log 93562 - Backup Completed11