V2P Job Can Fail with ORA-00210, ORA-27047 When Opening the Database (KBA2795)

Applicable Delphix Versions

Issue

Provisioning a physical Oracle database to a Linux target host using the Virtual to Physical (V2P) facility can fail with errors similar to those below, reporting a failure to read the control file.

ALTER DATABASE   MOUNT
ORA-00210: cannot open the specified control file
ORA-00202: control file: '/u01/oradata/testdb/data/+DATA01/testdb1/controlfile/current.160518'
ORA-27047: unable to read the header block of file
Linux-x86_64 Error: 22: Invalid argument
Additional information: 1
ORA-205 signalled during: ALTER DATABASE   MOUNT...

However, the control file is present in the specified directory and the OS user specified for the provision job has the required permissions to read and write to the file.

Troubleshooting

Confirm whether the underlying disk on the Linux host uses a 4KB sector or block size.  For example, this device uses a 4KB sector size.

# blockdev --getbsz /dev/sda1
4096

Note that this does not refer to the database's db_block_size but rather the size of the blocks used by the physical disk to store data.  These will usually be either 512 bytes or 4096 bytes.

If a 4KB disk sector size is in use, check whether Direct I/O is being used by Oracle.  This will be the case if the filesystemio_options database parameter is set to 'DIRECTIO' or 'SETALL'.

Resolution

Change the filesystemio_options database parameter to 'ASYNCH' or 'NONE' to disable Direct I/O.  This parameter can be modified during the initial V2P job configuration.

Additional Information

The issue can also occur during a manual open of the database if the V2P job has been set not to open the database after completing the data copy operation.

External Links

The following Oracle document states that Direct I/O is not supported with Linux devices using a 4KB sector size.

Supporting 4K Sector Disks (Doc ID 1133713.1)