Getting Error ‘ Unable to obtain lock on SERVER_NAME.lok.’ on Starting UIM Server


UIM Server fails to start with following error:

Following error might also be observed:

Root Cause:

There can be 2 reasons for this issue:

The [server name].lok indicates that the server with name [server name] is running. This is used to prevent a server from being booted twice. This error indicates that server user tried to restart is already up & running.
This issue can come up if the server didn’t previously shut down gracefully and thus couldn’t unlock (delete) its lok files.


Verify if server user trying to restart is already up & running. If running then shutdown the server first before restarting it. Any of the following methods can be used to verify
1.1 If Admin Server try to access WebLogic Administration console.
1.2 If Manage Server verify its status from WebLogic Administration console.
1.3 Use WLST to connect to the server. Access WLST command details here.
1.4 Use ps -eaf | grep java
1.5 Use lsof -i -P -n | grep LISTEN | grep

If its verified that server is not running already, delete [server name].lok file. This file is placed in $WLS_Domain/servers/$Server_Name/tmp directory.
If error is observed for EmbeddedLDAP.lok file as well, delete it too. This file is placed in $WLS_Domain/servers/$Server_Name/data/ldap/ldapfiles directory.

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