Lvm [12446]: Another thread is handling an event. Waiting, lvm12446

Lvm [12446]: Another thread is handling an event. Waiting, lvm12446

When checking a Linux server, a large number of "lvm [12446]: Another thread is handling an event. Waiting..." are found in the log ..."

Jul  4 00:01:42 localhost lvm[12446]: Another thread is handling an event. Waiting...

Jul  4 00:09:36 localhost lvm[12446]: Another thread is handling an event. Waiting...

Jul  4 00:13:42 localhost lvm[12446]: Another thread is handling an event. Waiting...

Jul  4 00:13:43 localhost lvm[12446]: Extension of snapshot VolGroup05/LogVol00-PS-user-snapshot finished successfully.

Jul  4 00:13:43 localhost lvm[12446]: dm_task_run failed, errno = 9, Bad file descriptor

Jul  4 00:14:42 localhost lvm[12446]: Extension of snapshot VolGroup05/LogVol00-PS-user-snapshot finished successfully.

Jul  4 00:15:52 localhost lvm[12446]: Extension of snapshot VolGroup05/LogVol00-PS-user-snapshot finished successfully.

Jul  4 00:17:02 localhost lvm[12446]: Another thread is handling an event. Waiting...

Jul  4 00:17:02 localhost lvm[12446]: Extension of snapshot VolGroup05/LogVol00-PS-user-snapshot finished successfully.

Jul  4 00:17:46 localhost lvm[12446]: Another thread is handling an event. Waiting...

Jul  4 00:18:52 localhost lvm[12446]: Extension of snapshot VolGroup05/LogVol00-PS-user-snapshot finished successfully.

Jul  4 00:19:42 localhost lvm[12446]: Extension of snapshot VolGroup05/LogVol00-PS-user-snapshot finished successfully.

Jul  4 00:20:32 localhost lvm[12446]: Snapshot VolGroup05-LogVol00--PS--user--snapshot is now 80% full. 

Jul  4 00:20:32 localhost lvm[12446]: Extension of snapshot VolGroup05/LogVol00-PS-user-snapshot finished successfully.

Jul  4 00:23:12 localhost lvm[12446]: Snapshot VolGroup05-LogVol00--PS--user--snapshot is now 85% full. 

Jul  4 00:23:12 localhost lvm[12446]: Another thread is handling an event. Waiting...

Jul  4 00:23:12 localhost lvm[12446]: Extension of snapshot VolGroup05/LogVol00-PS-user-snapshot finished successfully.

Jul  4 00:23:12 localhost lvm[12446]: dm_task_run failed, errno = 9, Bad file descriptor

Jul  4 00:26:09 localhost lvm[12446]: Another thread is handling an event. Waiting...

Jul  4 00:26:52 localhost last message repeated 2 times

Jul  4 00:26:52 localhost lvm[12446]: Snapshot VolGroup05-LogVol00--PS--user--snapshot is now 90% full. 

Jul  4 00:26:52 localhost lvm[12446]: Extension of snapshot VolGroup05/LogVol00-PS-user-snapshot finished successfully.

Jul  4 00:28:52 localhost lvm[12446]: Another thread is handling an event. Waiting...

Jul  4 00:28:52 localhost lvm[12446]: Snapshot VolGroup05-LogVol00--PS--user--snapshot is now 95% full. 

Jul  4 00:28:52 localhost lvm[12446]: Extension of snapshot VolGroup05/LogVol00-PS-user-snapshot finished successfully.

Jul  4 00:28:52 localhost lvm[12446]: dm_task_run failed, errno = 9, Bad file descriptor

Jul  4 00:31:07 localhost kernel: device-mapper: snapshots: Invalidating snapshot: Unable to allocate exception.

Jul  4 00:34:59 localhost lvm[12446]: Another thread is handling an event. Waiting...

Jul  4 00:35:42 localhost lvm[12446]: Another thread is handling an event. Waiting...

Jul  4 00:42:29 localhost lvm[12446]: Another thread is handling an event. Waiting...

Jul  4 00:44:16 localhost lvm[12446]: Another thread is handling an event. Waiting...

Jul  4 00:45:49 localhost lvm[12446]: Another thread is handling an event. Waiting...

Jul  4 00:46:59 localhost last message repeated 3 times

Jul  4 00:48:49 localhost last message repeated 2 times

On the Redhat official website, we can see related information "What does" lvm: Another thread is handling an event. Waiting... "log messages mean on Red Hat Enterprise Linux 6? "As follows:

Problem

• Lvm event log messages
• Continuous messages filling/var/log/messages
  

  lvm: Another thread is handling an event, Waiting...
  lvm: Another thread is handling an event, Waiting...

Resolution

• These messages can safely be ignored at this stage. They are verbose messages that do not indicate any error has occurred.
• Red Hat are planning to remove these messages from the lvm2 package in a future release of Red Hat Enterprise Linux 6.

Root Cause

• Dmeventd daemon montors for events that need to occur on device-mapper devices.
  • There are segments of code that can only be entered by one thread at a time.
  • If a second thread tries to enter the code section, it will be forced to wait until the first thread has exited. This message is printed when a process is forced to wait.
• There is currently no eviical that there is any problem with locking access to critical code in dmeventd.

Diagnostic procedure

If the following symptoms are present on your system, then this article may apply to your issue:

• Your lvm2 package is 2.02.87-6. el6 or earlier.
• You have more than 1 LVM snapshots on the system.

• Periodically, the following messages appear in/var/log/messages:

  Raw

      lvm: Another thread is handling an event. Waiting...    lvm: Another thread is handling an event. Waiting...

According to official documents, this message can be ignored. This occurs in your system. When your system meets the following conditions:

When your lvm2 package version is 2.02.87-6. el6 or earlier.

When your system has more than one LVM Snapshot

Comparing and referring to the operating system version of the local machine, we found that lvm2 version is indeed lower than 2.02.87-6. el6. In addition, the system does have multiple LVM snapshots. The only difference is that Red Hat Enterprise Linux Server release 5.7 is not Red Hat Enterprise Linux (RHEL) 6.

[root@localhost ~]# rpm -qa | grep lvm

lvm2-2.02.84-6.0.1.el5

system-config-lvm-1.1.5-9.el5

[root@localhost ~]# cat /etc/redhat-release 

Red Hat Enterprise Linux Server release 5.7 (Tikanga)

In addition, check the process 12446, which is indeed/sbin/dmeventd.

[root@localhost ~]# ps -ef | grep  12446 

root     12446     1  0 Jul02 ?        00:07:51 /sbin/dmeventd

root     26043 23106  0 11:06 pts/6    00:00:00 grep 12446

This error message keeps appearing in system logs. It is strange that other servers in the same environment do not have this problem. It should be caused by some problems. When doing a VG scan, it was found that there were some error messages such as/dev/VolGroup03/LogVol00-PS-user-snapshot: read failed after 0 of 4096 at 0: Input/output error, suspected this caused, however, the production environment cannot be changed. You need to test and verify the environment before processing in the production environment. Currently, You do not have permission or resource processing. You need the help of a system administrator.