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Mounting DBFS using dbfs_client Hangs " FO - Unregister callback" (Doc ID 1606070.1)

Last updated on JANUARY 24, 2020

Applies to:

Oracle Database - Enterprise Edition - Version and later
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Information in this document applies to any platform.


While configuring DBFS on the client machine, the following command hangs:

    $ $ORACLE_HOME/bin/dbfs_client dbfs_owner@EAI01D -o failover /appl/home/oracle/dbfs_bla
    @ Password:
    ... hangs forever ...

This client machine is trying to mount the DBFS from a database on a different machine.    
The required fuse is present

    $ rpm -qa | grep -i fuse

When you take the trace of the command

    $ $ORACLE_HOME/bin/dbfs_client dbfs_owner@EAI01D -o failover -otrace_file=/tmp/dbfs.out -otrace_level=1 -otrace_size=0 /appl/home/oracle/dbfs_bla
    @ Password:

You see the following in the trace file:

    [28fa5700 10/09/13 11:55:54.921796 LcdfFso.cpp:165            ] DEBUG: FSO    DecRefcnt(/) ref:1
    [28fa5700 10/09/13 11:55:54.921807 LcdfLock.cpp:230           ] DEBUG: Global Lock - unlock
    [28fa5700 10/09/13 11:55:54.921822 LcdfLock.cpp:242           ] DEBUG: Global Lock (R) rdwr:0
    [28fa5700 10/09/13 11:55:54.921839 LcdfDBPool.cpp:348         ] DEBUG: releaseSession FOCTX delete 0x7f98080008f0
    [28fa5700 10/09/13 11:55:54.921861 LcdfDBPool.cpp:646         ] DEBUG: FO - Unregister callback...
    [1b3f1700 10/09/13 11:55:55.077967 ./LcdfThreadPool.h:276     ] DEBUG: Retrying after some time .110. 1381312555 79439539
    [1a9f0700 10/09/13 11:55:55.078062 ./LcdfThreadPool.h:276     ] DEBUG: Retrying after some time .110. 1381312555 79549954
    [1a9f0700 10/09/13 11:56:00.078384 ./LcdfThreadPool.h:276     ] DEBUG: Retrying after some time .110. 1381312560 79970050


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